IceToad

This disable common startup programs, settings, and drivers to troubleshoot issues in Windows XP. This procedure is known as The "clean booting."
You should use this procedure only to troubleshoot error messages or behaviors when you have been unable to determine the cause of the issue. Following these steps results in a temporary loss of some functionality. Restoring the settings restores the functionality, but it may result in the return of the original error message or behavior.

How to Perform a Clean Boot in Windows XP
NOTE :You must be logged on as an administrator or a member of the Administrators group in to complete this procedure. If your computer is connected to a network, network policy settings may also prevent you from completing this procedure. WinXpFix.com
1. In Windows click on Start , click Run , type msconfig in the Open box, and then click OK .
2. On the General tab, click Selective Startup , and then clear all of the subsequent check boxes. You will not be able to clear the Use Original BOOT.INI check box.
3. Click OK , and then you need to click Restart to restart your computer.
4. After Windows starts, you need to determine whether the symptoms are still present. Click Start , click Run , type msconfig in the Open box, and then click OK .
NOTE: It is important for you to look closely at the General tab to ensure that the check boxes you cleared are still cleared. Go to step 6 if none of the check boxes are selected. If you see a disabled or dimmed check box, your computer is not truly "clean-booted" and you may need assistance from the manufacturer of the program that places a check mark back into Msconfig.
5. On the General tab, click Selective Startup , and then clear all of the subsequent check boxes. You will not be able to clear the Use Original Boot.ini check box.
6. Starting with the first available check box (Process System.ini File), select each check box one at a time, and restart the computer as prompted until the problem is reproduced.
7. Once the problem reappears, click the tab that corresponds to the selected file. For example, if the problem reappears after selecting the Win.ini file, click the WIN.INI tab in System Configuration Utility.
NOTE : Microsoft strongly recommends that you do not use System Configuration Utility to modify the Boot.ini file on your computer without the direction of a Microsoft support professional. Doing so may render your computer unusable:-(

How to Start the Windows Installer Service:
NOTE : The Windows Installer service does not start throughout a clean boot. In order to use the Windows Installer throughout a clean boot, you must start the service manually. WinXpFix.com
1. In Windows click Start , and then right-click on My Computer .
2. On the shortcut menu, click on Manage.
3. In the left pane of the Computer Management window, click Services and Applications , and then click Services .
4. In the right pane, scroll down to Windows Installer, and then right-click on Windows Installer .
5. On the shortcut menu, click on Start .

How to Return from a Clean Boot State:
1. Click on Start , then click Run , type msconfig in the Open box, and then click OK .
2. On the General tab, click Normal Startup - load all device drivers and services .
3. Click on OK . Click Restart when you are prompted to restart your computer. Perform a Clean Boot in Windows XP