XP SP3 Pro Screen Goes Black after Logoff When Attempting to Switch Users

Hi Geeks,

Have just recovered from nasty virus attack (Thanks TimW in Malware). Am trying to be a good little computer user and set up a non-admin account to surf web to help reduce future problems.

My normal HP_Admin account boots, runs and logs off okay. I can either Log Off or Switch User to one of my kids' non-admin accounts just fine. However, upon exiting their accounts, the logoff process tells me that it is saving user settings, then goes to a black screen. Same thing happens when I now setup a new user non-admin account for web surfing etc. Event logs give me same Userenv event ID's 1517 and 1524 for all accounts that attempt to logoff. At some point in past (seems to me to be b4 we ran CCleaner and various malware removal utilities) that logoffs and switch users were fine) but I am not confident of that reply because kids usually just share my account. We have also in last 6 month enabled networking settings for wireless laptop networking with this desktop ... I mention that because one of messages seemed to have to do with roaming accounts - perhaps we have a setting wrong somewhere?

thanks for any help,
dood1emom