In addition to Dev and Ron's advice:
For additional help see
www.dougknox.com, Win XP Utilities, Create Emergency
Copies of Critical XP System Utilities. This small VB Program will create
backup, usable copies of Task Manger, Regedit and MSConfig (named
Taskmgr1.exe, Regedit.com and MSConfig1.exe) in a new folder
C:\EmergencyUtil. Many virus programs will intercept these programs, based
on their original file name. The modified file names, allow them to be run.
Open Windows Explorer to C:\EmergencyUtil and double click the application
you need. The next revision will allow you to browse for the folder you
want to place the backups in.