Pen Drive inflected with autorun.inf,explorer.exe and isetup.exe

When i insert any pen-drive to my laptop(running XP SP2) it just inflects and drive with following files
autorun.inf,
explorer.exe and
isetup.exe

They all are hidden or being system files.
Even i delete the files it again appears after few seconds.
I havenot got the effected of this on my system or to my other files. but it is annoying to we all.
Please help to get ride of these files.

more info:
Latest AVG anit-virus and anti-spyware cant detect them.