If an essential Windows file gets whacked by a virus or otherwise gets corrupted, you can restore it from the Windows CD. Search the CD for the filename, replacing the last character with an underscore; for example, Notepad.ex_. If it's found, open a command prompt and enter the command 'EXPAND', followed by the full pathname of the file and of the desired destination. Example:
EXPAND D:\SETUP\NOTEPAD.EX_ C:\Windows\NOTEPAD.EXE
If either pathname contains any spaces, surround it with double quotes. If the file isn't found, search on the unmodified filename. It will probably be inside a CAB file, which Windows XP treats as a folder. Simply right-drag and copy the file to the desired location. When the search is done, open a command prompt and enter 'EXTRACT /L' followed by the desired location, the full pathname of the CAB file, and the desired filename. Example:
EXTRACT /L C:\Windows D:\I386\Driver.cab Notepad.exe
