Showing posts with label Security. Show all posts
Showing posts with label Security. Show all posts

Wednesday, August 6, 2008

How To Remove and Add Right-Click Menu Items from Files and Folders

Removing Items

A lot of programs you install will add themselves to the right-click menu of your files and/or folders. And most times, you have no choice in the matter and, as a result, your right-click menu can get very long with added items you don't even use. The last person I was helping with this had a right context menu so long that the Rename option was no longer visible!
Fortunately, you can easily remove those unwanted menu items, if you know the registry values to edit. And it's not at all difficult once you know the keys responsible for the additions.

For Files, the secret lies in the "context menu handlers" under the shellex subkey for "All Files" which, in the registry, is nothing but an asterisk - like a dos wildcard, which means the values entered apply to all files. It is at the very top of the Root key, right here:

HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers

Click the the + sign next to the ContextMenuHandlers key, to expand it.
Now you will see some of the programs that have added items to your right-click menu. Simply delete the program keys you don't want.
Yup! It's that simple. If deleting makes you uneasy, just export the key before deleting it. Or, instead of deleting the values, disable them. Simply double click the default value for the program on the right hand pane and rename the clsid value by placing a period or dash in front of it.
ie; - {b5eedee0-c06e-11cf-8c56-444553540000}
Then exit the registry, refresh, and right click a file to see if the item was removed from the menu.
Some programs - like WinZip or WinRar - will add several items to your right click menu but all of them will be removed by deleting or disabling their one context menu handler.

Note that the above key only applies to the right click menu of files.
To remove entries from the right click context menu of folders, you need to navigate to the Folder and Drive keys:

HKEY_CLASSES_ROOT\Folder\shellex\ContextMenuHandlers
HKEY_CLASSES_ROOT\Drive\shellex\ContextMenuHandlers

All you have to do is follow the same procedure as for Files - either disable or delete items you wish to remove.

Adding Items

Adding Items to the right click menu of Files and Folders is also fairly simple using the Registry. It just involves the creation of a few new keys for each item you wish to add. You edit the same keys used for removing items. Let's use Notepad as an example of an item you'd like to add to the right click menu of all your files or folders.

For folders, go to this key:
HKEY_CLASSES_ROOT\Folder
Click the + sign next to Folder and expand it so that the Shell key is visible. Right click the Shell key and choose New>Key and name the key Notepad or whatever else you'd prefer (whatever the key is named is what will appear in the right-click menu). Now right click the new key you made and create another key named Command. Then, in the right hand pane, double click "Default" and enter Notepad.exe as the value.
Exit the registry, refresh, and right click any folder. Notepad should now be on the context menu.


For files, go here again:

HKEY_CLASSES_ROOT\*
Expand the * key and see if a Shell key exists. If it does exist, follow the same procedure as for folders. If it does not exist, you'll have to create a new Shell first. Just right click the * key and choose New>Key and name it Shell. Then right click the Shell key and continue on the same way you did for adding items to the right click menu of folders.
Once done, Notepad should appear as an option in the right click menu of all your files.
Vic Ferri owns the very popular WinTips and Tricks email group. He is also in charge of the Printing Tips and Registry Tips pages at Linda's Computer Stop.

Thursday, July 10, 2008

System Changes To Foil Hackers And Browser Hijackers

Hackers and Browser Hijacking is one area of the Net that affects everyone at some stage.

In addition to having third party utilities such as SpyBot, Anti Virus scanners and firewalls installed there are some changes that can be made to Windows 2000/XP. Below are some details to make your system safer from hackers and hijackers.

Some of these tips require editing of the Registry so it is wise to either backup the registry and/or create a Restore Point.

1. Clearing the Page File at Shutdown

Windows 2000/XP paging file (Sometimes called the Swap File) can contain sensitive information such as plaintext passwords. Someone capable of accessing your system could scan that file and find its information. You can force windows to clear out this file.

In the registry navigate to HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerMemory Management and add or edit the DWORD ClearPageFileAtShutdown. Set it to 1.

Note that when you do this, the system will take much longer to shut down: a system with a really big Page File (! Gig or more) may take a minute or two longer.

2. Disable the POSIX and OS/2 Subsystem.

Windows 2000 and XP come with little-documented subsystems it at allow compatibility with UNIX and OS/2 systems These rues systems are enabled by default but so rarely used that they are best off bring disabled completely to prevent possible service hijackings.

To disable these subsystems, open the registry and navigate to HKEY LOCAL MACHINESYSTEMCurrentControlSetControlSession ManagerSubSystems. Delete the subkeys Os2 and Posix. then reboot.

3. Never leave default passwords blank.

On installation, Windows 2000 sets up an Administrator account with total system access and prompts for a password. Guess what: by default, it allows that password to be blank. If a user doesn't want to type a password, he can simply click Next and the system will be an open door for anyone who wants to log on. Always opt for a password of some kind when setting up the default account on a machine.

4. Install Windows In a different directory.

Windows usually installs itself in the WINDOWS directory. Windows NT 4 0 and 2000 Will opt for WINNT. Many worms and other rogue programs assume this to be the case and attempt to exploit those folders files. To defeat this install Windows to another directory when you're setting it up - you can specify the name of the directory during setup. WINDIR is okay; so some people use WNDWS - A few (not that many) programs may not install properly if you install Windows to another folder but t hey are very few and they are far between

5. Fake out hackers with a dummy Administrator account

Since the default account in Windows 2000 is always named Administrator, an enterprising hacker can try to break into your system by attempting to guess the password on that account. It you never bothered to put a password on that account, say your prayers.

Rather than be a sucker to a hacker, put a password on the Administrator account it you haven't done so already. Then change the name of the Administrator account. You'll still be able to use the account under its new name, since Windows identifies user accounts by a back-end ID number rather than the name. Finally, create a new account named Administrator and disable it. This should frustrate any would -be break-ins.

You can add new accounts and change the names of existing accounts in Windows 2000 through the Local Users and Groups snap in. Right-click on My Computer, select Manager, open the Local Users and Groups subtree, look in the Users folder and right-click on any name to rename it. To add a new user, right-click on the containing folder and select New User. Finally, to disable an account, double-click it, check the Account is disabled box and click OK.

Don't ever delete the original Administrator account. Some programs refuse to install without it and you might have to log in under that account at some point to setup such software. The original Administrator account is configured with a security ID that must continue to be present in the system.

6. Disable the Guest account

Windows XP comes with a Guest account that's used for limited access, but it's still possible to do some damage with it. Disable it completely if you are not using it. Under Control Panel, select User Accounts, click on Guest Account and then select Turn Off the Guest Account.

7. Set the Hosts file to read-only to prevent name hijacking.

This one's from (and to a degree, for) the experts. The HOSTS file is a text file that all flavors of Windows use to hold certain network addresses that never change. When a network name and address is placed in HOSTS, the computer uses the address listed there for that network name rather than performing a lookup (which can take time). Experts edit this file to place their most commonly-visited sites into it, speeding things up considerably.

Unfortunately hijackers and hackers also love to put their own information into it - redirecting people from their favorite sites to places they don't want to go. One of the most common entries in HOSTS is local host which is set 1770.0.1. This refers to the local machine and if this entry is damaged the computer can behave very unpredictably.

To prevent HOSTS from being hijacked, set it to read-only. Go to the folder %Systemroot%system32driversetc, right-click on HOSTS, select Properties check the Read-Only box and click OK. If you want to add your own entries to HOSTS, you can unprotect it before doing so, but always remember to set it to read-only after you're done.

8. Disallow changes to IE settings through IE

This is another anti hijacker tip. IE can be set so that any changes to its settings must be performed through the Internet icon in the Control Panel, rather than through IE's own interface. Some particularly unscrupulous programs or sites try to tamper with setting by accessing the Tools, Options menu in IE. You can disable this and still make changes to IE's settings through the Control Panel.

Open the Registry and browse to HKEY_CURRENT_USER SoftwarePoliciesMicrosoftInternet ExplorerRestrictions. Create or edit a new DWORD value named NoBrowserUptions and set it to 1 (this is a per-user setting). Some third-party programs such as Spybot Search And Destroy allow you to toggle this setting.

You can also keep IE from having other programs rename its default startup page, another particularly annoying form of hijacking. Browse to HKEY.CURRENT USERSoftwarePolicies MicrosoftInternet ExploreControl Panel and add or edit a DWORD, Homepage and set it to 1.

9. Turn off unneeded Services

Windows 2000 and XP both come with many background services that don't need to he running most of the time: Alerter, Messenger, Server (If you're running a standalone machine with no file or printer shares), NetMeeting Remote Desktop Sharing, Remote Desktop Help Session Manager (the last two if you're not using Remote Desktop or NetMeeting), Remote Registry, Routing and Remote Access (if you're not using Remote Access), SSDP Discovery Service, Telnet, and Universal Plug and Play Device Host.

A good resource and instruction on which of these services can be disabled go to http://www.blkviper.com/WinXP/

10. Disable simple File Shares.

In Windows XP Professional, the Simple File Sharing mode is easily exploited, since it’s a little too easy to share out a file across your LAN (or the NET at large). To turn it off, go m My Computer, click Tools, Folder Option and the View tab, and uncheck Use Simple file sharing (Recommended). Click OK. When you do this you can access the Security tab in the Properties window for all folders; set permissions for folders; and take ownership of objects (but not in XP Home)

10 Security Enhancements

Before you spend a dime on security, there are many precautions you can take that will protect you against the most common threats.

1. Check Windows Update and Office Update regularly (_http://office.microsoft.com/productupdates); have your Office CD ready. Windows Me, 2000, and XP users can configure automatic updates. Click on the Automatic Updates tab in the System control panel and choose the appropriate options.

2. Install a personal firewall. Both SyGate (_www.sygate.com) and ZoneAlarm (_www.zonelabs.com) offer free versions.


3. Install a free spyware blocker. Our Editors' Choice ("Spyware," April 22) was SpyBot Search & Destroy (_http://security.kolla.de). SpyBot is also paranoid and ruthless in hunting out tracking cookies.

4. Block pop-up spam messages in Windows NT, 2000, or XP by disabling the Windows Messenger service (this is unrelated to the instant messaging program). Open Control Panel | Administrative Tools | Services and you'll see Messenger. Right-click and go to Properties. Set Start-up Type to Disabled and press the Stop button. Bye-bye, spam pop-ups! Any good firewall will also stop them.

5. Use strong passwords and change them periodically. Passwords should have at least seven characters; use letters and numbers and have at least one symbol. A decent example would be f8izKro@l. This will make it much harder for anyone to gain access to your accounts.

6. If you're using Outlook or Outlook Express, use the current version or one with the Outlook Security Update installed. The update and current versions patch numerous vulnerabilities.

7. Buy antivirus software and keep it up to date. If you're not willing to pay, try Grisoft AVG Free Edition (Grisoft Inc., w*w.grisoft.com). And doublecheck your AV with the free, online-only scanners available at w*w.pandasoftware.com/activescan and _http://housecall.trendmicro.com.

8. If you have a wireless network, turn on the security features: Use MAC filtering, turn off SSID broadcast, and even use WEP with the biggest key you can get. For more, check out our wireless section or see the expanded coverage in Your Unwired World in our next issue.

9. Join a respectable e-mail security list, such as the one found at our own Security Supersite at _http://security.ziffdavis.com, so that you learn about emerging threats quickly and can take proper precautions.

10. Be skeptical of things on the Internet. Don't assume that e-mail "From:" a particular person is actually from that person until you have further reason to believe it's that person. Don't assume that an attachment is what it says it is. Don't give out your password to anyone, even if that person claims to be from "support."

10 reasons why PCs crash U must Know


Fatal error: the system has become unstable or is busy," it says. "Enter to return to Windows or press Control-Alt-Delete to restart your computer. If you do this you will lose any unsaved information in all open applications."

You have just been struck by the Blue Screen of Death. Anyone who uses Mcft Windows will be familiar with this. What can you do? More importantly, how can you prevent it happening?

  • Hardware conflict

The number one reason why Windows crashes is hardware conflict. Each hardware device communicates to other devices through an interrupt request channel (IRQ). These are supposed to be unique for each device.

For example, a printer usually connects internally on IRQ 7. The keyboard usually uses IRQ 1 and the floppy disk drive IRQ 6. Each device will try to hog a single IRQ for itself.

If there are a lot of devices, or if they are not installed properly, two of them may end up sharing the same IRQ number. When the user tries to use both devices at the same time, a crash can happen. The way to check if your computer has a hardware conflict is through the following route:

* Start-Settings-Control Panel-System-Device Manager.

Often if a device has a problem a yellow '!' appears next to its description in the Device Manager. Highlight Computer (in the Device Manager) and press Properties to see the IRQ numbers used by your computer. If the IRQ number appears twice, two devices may be using it.

Sometimes a device might share an IRQ with something described as 'IRQ holder for PCI steering'. This can be ignored. The best way to fix this problem is to remove the problem device and reinstall it.

Sometimes you may have to find more recent drivers on the internet to make the device function properly. A good resource is www.driverguide.com. If the device is a soundcard, or a modem, it can often be fixed by moving it to a different slot on the motherboard (be careful about opening your computer, as you may void the warranty).

When working inside a computer you should switch it off, unplug the mains lead and touch an unpainted metal surface to discharge any static electricity.

To be fair to Mcft, the problem with IRQ numbers is not of its making. It is a legacy problem going back to the first PC designs using the IBM 8086 chip. Initially there were only eight IRQs. Today there are 16 IRQs in a PC. It is easy to run out of them. There are plans to increase the number of IRQs in future designs.

  • Bad Ram

Ram (random-access memory) problems might bring on the blue screen of death with a message saying Fatal Exception Error. A fatal error indicates a serious hardware problem. Sometimes it may mean a part is damaged and will need replacing.

But a fatal error caused by Ram might be caused by a mismatch of chips. For example, mixing 70-nanosecond (70ns) Ram with 60ns Ram will usually force the computer to run all the Ram at the slower speed. This will often crash the machine if the Ram is overworked.

One way around this problem is to enter the BIOS settings and increase the wait state of the Ram. This can make it more stable. Another way to troubleshoot a suspected Ram problem is to rearrange the Ram chips on the motherboard, or take some of them out. Then try to repeat the circumstances that caused the crash. When handling Ram try not to touch the gold connections, as they can be easily damaged.

Parity error messages also refer to Ram. Modern Ram chips are either parity (ECC) or non parity (non-ECC). It is best not to mix the two types, as this can be a cause of trouble.

EMM386 error messages refer to memory problems but may not be connected to bad Ram. This may be due to free memory problems often linked to old Dos-based programmes.

  • BIOS settings

Every motherboard is supplied with a range of chipset settings that are decided in the factory. A common way to access these settings is to press the F2 or delete button during the first few seconds of a boot-up.

Once inside the BIOS, great care should be taken. It is a good idea to write down on a piece of paper all the settings that appear on the screen. That way, if you change something and the computer becomes more unstable, you will know what settings to revert to.

A common BIOS error concerns the CAS latency. This refers to the Ram. Older EDO (extended data out) Ram has a CAS latency of 3. Newer SDRam has a CAS latency of 2. Setting the wrong figure can cause the Ram to lock up and freeze the computer's display.

Mcft Windows is better at allocating IRQ numbers than any BIOS. If possible set the IRQ numbers to Auto in the BIOS. This will allow Windows to allocate the IRQ numbers (make sure the BIOS setting for Plug and Play OS is switched to 'yes' to allow Windows to do this.).

  • Hard disk drives

After a few weeks, the information on a hard disk drive starts to become piecemeal or fragmented. It is a good idea to defragment the hard disk every week or so, to prevent the disk from causing a screen freeze. Go to

* Start-Programs-Accessories-System Tools-Disk Defragmenter

This will start the procedure. You will be unable to write data to the hard drive (to save it) while the disk is defragmenting, so it is a good idea to schedule the procedure for a period of inactivity using the Task Scheduler.

The Task Scheduler should be one of the small icons on the bottom right of the Windows opening page (the desktop).

Some lockups and screen freezes caused by hard disk problems can be solved by reducing the read-ahead optimisation. This can be adjusted by going to

* Start-Settings-Control Panel-System Icon-Performance-File System-Hard Disk.

Hard disks will slow down and crash if they are too full. Do some housekeeping on your hard drive every few months and free some space on it. Open the Windows folder on the C drive and find the Temporary Internet Files folder. Deleting the contents (not the folder) can free a lot of space.

Empty the Recycle Bin every week to free more space. Hard disk drives should be scanned every week for errors or bad sectors. Go to

* Start-Programs-Accessories-System Tools-ScanDisk

Otherwise assign the Task Scheduler to perform this operation at night when the computer is not in use.

  • Fatal OE exceptions and VXD errors

Fatal OE exception errors and VXD errors are often caused by video card problems.

These can often be resolved easily by reducing the resolution of the video display. Go to

* Start-Settings-Control Panel-Display-Settings

Here you should slide the screen area bar to the left. Take a look at the colour settings on the left of that window. For most desktops, high colour 16-bit depth is adequate.

If the screen freezes or you experience system lockups it might be due to the video card. Make sure it does not have a hardware conflict. Go to

* Start-Settings-Control Panel-System-Device Manager

Here, select the + beside Display Adapter. A line of text describing your video card should appear. Select it (make it blue) and press properties. Then select Resources and select each line in the window. Look for a message that says No Conflicts.

If you have video card hardware conflict, you will see it here. Be careful at this point and make a note of everything you do in case you make things worse.

The way to resolve a hardware conflict is to uncheck the Use Automatic Settings box and hit the Change Settings button. You are searching for a setting that will display a No Conflicts message.

Another useful way to resolve video problems is to go to

* Start-Settings-Control Panel-System-Performance-Graphics

Here you should move the Hardware Acceleration slider to the left. As ever, the most common cause of problems relating to graphics cards is old or faulty drivers (a driver is a small piece of software used by a computer to communicate with a device).

Look up your video card's manufacturer on the internet and search for the most recent drivers for it.

  • Viruses

Often the first sign of a virus infection is instability. Some viruses erase the boot sector of a hard drive, making it impossible to start. This is why it is a good idea to create a Windows start-up disk. Go to

* Start-Settings-Control Panel-Add/Remove Programs

Here, look for the Start Up Disk tab. Virus protection requires constant vigilance.

A virus scanner requires a list of virus signatures in order to be able to identify viruses. These signatures are stored in a DAT file. DAT files should be updated weekly from the website of your antivirus software manufacturer.

An excellent antivirus programme is McAfee VirusScan by Network Associates ( www.nai.com). Another is Norton AntiVirus 2000, made by Symantec ( www.symantec.com).

  • Printers

The action of sending a document to print creates a bigger file, often called a postscript file.

Printers have only a small amount of memory, called a buffer. This can be easily overloaded. Printing a document also uses a considerable amount of CPU power. This will also slow down the computer's performance.

If the printer is trying to print unusual characters, these might not be recognised, and can crash the computer. Sometimes printers will not recover from a crash because of confusion in the buffer. A good way to clear the buffer is to unplug the printer for ten seconds. Booting up from a powerless state, also called a cold boot, will restore the printer's default settings and you may be able to carry on.

  • Software

A common cause of computer crash is faulty or badly-installed software. Often the problem can be cured by uninstalling the software and then reinstalling it. Use Norton Uninstall or Uninstall Shield to remove an application from your system properly. This will also remove references to the programme in the System Registry and leaves the way clear for a completely fresh copy.

The System Registry can be corrupted by old references to obsolete software that you thought was uninstalled. Use Reg Cleaner by Jouni Vuorio to clean up the System Registry and remove obsolete entries. It works on Windows 95, Windows 98, Windows 98 SE (Second Edition), Windows Millennium Edition (ME), NT4 and Windows 2000.

Read the instructions and use it carefully so you don't do permanent damage to the Registry. If the Registry is damaged you will have to reinstall your operating system. Reg Cleaner can be obtained from www.jv16.org

Often a Windows problem can be resolved by entering Safe Mode. This can be done during start-up. When you see the message "Starting Windows" press F4. This should take you into Safe Mode.

Safe Mode loads a minimum of drivers. It allows you to find and fix problems that prevent Windows from loading properly.

Sometimes installing Windows is difficult because of unsuitable BIOS settings. If you keep getting SUWIN error messages (Windows setup) during the Windows installation, then try entering the BIOS and disabling the CPU internal cache. Try to disable the Level 2 (L2) cache if that doesn't work.

Remember to restore all the BIOS settings back to their former settings following installation.

  • Overheating

Central processing units (CPUs) are usually equipped with fans to keep them cool. If the fan fails or if the CPU gets old it may start to overheat and generate a particular kind of error called a kernel error. This is a common problem in chips that have been overclocked to operate at higher speeds than they are supposed to.

One remedy is to get a bigger better fan and install it on top of the CPU. Specialist cooling fans/heatsinks are available from www.computernerd.com or www.coolit.com

CPU problems can often be fixed by disabling the CPU internal cache in the BIOS. This will make the machine run more slowly, but it should also be more stable.

  • Power supply problems
With all the new construction going on around the country the steady supply of electricity has become disrupted. A power surge or spike can crash a computer as easily as a power cut.

If this has become a nuisance for you then consider buying a uninterrupted power supply (UPS). This will give you a clean power supply when there is electricity, and it will give you a few minutes to perform a controlled shutdown in case of a power cut.

It is a good investment if your data are critical, because a power cut will cause any unsaved data to be lost.