No Users to be seen!

[Guest]

I recently (2 months ago) completely reinstalled XP Home with 3 users, Peter
Jackie and Guest (built in). I use the welcome screen and have logged in well
since then. However this morning there were NO USERS on the welcome screen. I
used CTRL ALT DEL to get the log on dialog. Only one user would work. When I
got in I went to Control Panel and Users. It reported that the Current user
was not known (or similar) and I should close the comeputer and restart. This
of course made no difference.
Please could you help. I can find nothing on the Knowledgebase except
regarding PC Anywhere - this looks like the symptoms, but I don't have PC
Anywhere.
This machine has not connected to the internet since the reinstall.

Help

 

[null2006]

Try booting to Safe Mode and logging in as Administrator. You should be able to
check on the users there.

 

[Guest]

Yes I have done that, and the same thing - even says that the Current User
(ie Administrator) is not known.

Baffling this one. There must be something that I don't know about like a
service switched off. Any more ideas