Windows XP problem with start-up

[Guest]

I booted xp in safe mode to run antivirus programs. Upon completion, I ran
the defrag. Now xp will not allow me to log-on. It allows me to
ctrl-alt-del, supply a user name and password, displays 'loading personal
settings', then next displays 'saving personal settings' and proceeds to log
off. Any help is appreciated.

 

[Taurarian Fire]

http://support.microsoft.com/?kbid=313322
A User Logon Request Is Rejected Without Any Messages

http://www.winxptutor.com/wsaremove.htm
Quick Launch settings are not saved; Search Assistant Toolbar in Taskbar
Unable to logon to Windows after removing BlazeFind using a spyware removal utility?
Logon - Logoff loop, also caused by BlazeFind

Restore Winlogon\Userinit
http://www.kellys-korner-xp.com/xp_wel_screen.htm