1. Remove a program properly. If a program was manually deleted from the computer, there may still be files remaining on the system. These files can cause error messages to occur. Go to the Control Panel from the Start menu and click 'Add/Remove Programs.' Find the program in the list; click on it and click 'Uninstall.'
2. Start the computer in Safe Mode. Turn the computer off completely. Turn it back on and press the 'F8' key repeatedly until the Advanced Options Menu is displayed. Select 'Safe Mode' and log on.

3. Perform the action being carried out when the error last occurred. Safe Mode allows the system to run without unnecessary applications running in the background. If the error does not occur in Safe Mode, there is likely a program that is causing the error.
4. Uninstall programs added before the error began to occur. Remove the programs one at time by going to 'Add/Remove Programs' in the Control Panel, as described in Step 1. Use the computer normally between each uninstall. Determine which program was problematic when the error no longer occurs after a program is uninstalled.
5. Return the system to an earlier time when it was working properly. Go to the Start menu. Point to 'All Programs,' 'Accessories' and 'System Tools.' Click 'System Restore.' Follow the prompts to restore Windows XP to an earlier date when you know the errors were not occurring. Restart the computer when System Restore is complete.