Few weeks ago I reformatted my computer and installed a fresh copy of windows xp. Then i updated it to sp3 and all the security updates. It was fine with no pop ups or spyware. I plugged a usb drive to transfer some files and an error occured with the usb drive. so i unplugged it without the you can safely remove usb device. Then when i rebotted the computer explorer.exe kept restarting EVERY 10 SECS. I went into safe MODE and the same problem OCCURS. I donno what the problem can be. i ran sfc/ scannow but still no luckWhat antivirus software do you have?

When explorer.exe ends, does it come back up?There is a space between sfc and the /scannow switch...did you include this ?
ALSO the flash drive may be the culprit carrying the infection.
Run all your scans and re-boot after each one.
Then travel to the Virus and Spyware section and follow the instructions at the top of the page for posting your logs...does the explorer shell/icons move when clicked? if so back up ur files you may have Magistr
be careful it will rename/overwrite all of the files on ur C drive to a profane name (delteing all of your files on your hdd )

http://www.f-secure.com/v-descs/magistr.shtmlQuote

does the explorer shell/icons move when clicked? if so back up ur files you may have Magistr
be careful it will rename/overwrite all of the files on ur C drive to a profane name