not xp pro is it? and how many years have you had it? and did you recently go to windows update or did you recently enable automatic updates? do you have the install disc? if not, who installed the opsys for you?
Recently I tried to re-install an OEM XP Home onto its original machine and had the same trouble, plus I could not access MS update. Not sure what the trouble was but I'm glad I had my old unused Vista Basic (which cost me $299 at release) that installed just fine. If a malware scan does not help you may have to reactivate windows using the Genuine advantage tool, or use the phone number to manually activate.
not xp pro is it? and how many years have you had it? and did you recently go to windows update or did you recently enable automatic updates? do you have the install disc? if not, who installed the opsys for you?
Yes..XP Pro and I have had it for several years. I manually update Windows.
if it's legit ( the opsys ) turn off system restore. boot in safe mode with networking and do some malware/anti-virus scans. you can also try some online scans.......