Please go to Start → Run
Copy/paste the contents of the code box below into the Run box and click OK:

cmd /c del /a/f/q C:\Documents and Settings\Windows XP Pro\Local Settings\temp\avgnt.exe

Why have you been uninstall MCShield? This kind of malware is USB based and I can’t clean it up if you re-infect PC with infected USB. Therefore, you shall require MCShield for preventive.

Download & install MCShield again and repeat the procedure with scanning your USB mem devices. Please post here fresh AllScan.txt