This is symptomatic of a virus. 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.
Additionally, see the Win XP Utilities section for Startup Programs Tracker.
This small utility scans your system for startup programs and running
processes. It also allows you to create a log file that can be copied and
pasted into a newsgroup post. The contents of the program window are also
copied to the Windows Clipboard, automatically. For replies to newsgroup
posts, do NOT include the Running Services, unless its absolutely necessary.
Then update your antivirus software and scan your system, preferably from
Safe Mode.