The System File Checker can be a useful tool to help out if core system files become missing or corrupt.
This tutorial will explain how to perform it using Windows XP.
Click on start > All Programs > Accessories > Command Prompt
Once there type in sfc and a list of commands will be displayed giving you some options as to what to do.
Typically you want to then type in sfc /scannow to start an instant scan of the computer to check for files.
Basically at this point the scan process may take a good while and i suggest you do nothing on your computer while its scanning. If it encounters a problem it will let you know. You will also need your windows xp cd with the current service pack as is installed on your computer. For example if you have windows xp service pack 3 installed on your computer then you will need to use the windows xp service pack 3 cd!
In order to tell which service pack you have installed, simply right click on "My Computer" and select properties. Up will come a window with lots of information on it. You want where it says windows xp, a version like "home edition" or "professional edition" and then some where close to that will be a service pack number!
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