Problem is Jim, 1) I don't want a logon screen with a password prompt, 2) it changes all my settings, which I then have to go and redo. For example, I installed the following;

IE7
WMP11
Zoomplayer
Media Player Classic
Klite codec pack
a new theme (Royale Noir, proper MS signed theme for XP)
Sorted out my network stuff and mapped my network drives

then closed the language bar from the toolbar, sorted the systray shortcuts etc, changed the start menu to how I want it, and a few more things...

When it defaults back, it removes me from being the administrator, sets a default administrator account, and everything I have installed dissapears. IE is back to 6, WMP is back to 9, the theme has gone, the systray, start menu, task bar language bar etc all back to default, the programmes I installed gone, the codec pack gone, etc etc..

Then when I try and redo the changes most of the time it just reverts back again

touch wood this time it hasn't done it, and to be sure I've done a few reboots, shut downs etc, but I am not 100% sure it hasn't fluffed it again....

I've never had a PC do this, and all my PC's (and my mums) are set up as single user PC's, and the only user there is Admin under a name.... And they all work - except this one....