i am running xp sp1 and can boot fine to the logon screen. i can logon sucessfully to the network and the local machine but as soon as the desktop appears the 'loading settings' changes to 'logging off' and goes back to the 'hit ctr alt del to logon' screen. same thing happens if i try to logon again. same thing happens in all forms of safe mode. have run chkdsk and is fine, can also browse the disk when running ram os. any ideas on how to solve this?