ran full scan, recommended restart, on restart can't log in to windows

Help me please,

 

I'm running XP and I updated norton internet security and ran a full system scan.  The scan turned up items that needed attention.  Norton notified me that to remove threats i needed to restart my computer, i clicked restart now (recommended).  When I booted back up my login screen appeared so i clicked ok and windows started to come up, then my screen said logging off and returned me to login screen.

 

I then tried both safe mode and "last known good configuration" still same result.

 

Any help would be appreciated.