Another startup problem

Running XP Home
When I turn on the computer XP starts, get wallpaper with no icons, Welcome
chime then a few seconds later the exit chime and it goes to the Welcome
screen showing my Owner icon.
Click on Owner icon and it starts installing preferences and I get the
Welcome chime again, but it immediatly starts shutting down and I get the
Exit chime, then the message in the lower corner that it is safe to shutoff.

I have tried starting in Safe Mode and it does the same thing even though I
also have the Admin icon at the Welcome screen, it acts the same way starting
and immediatly shutting down using Admin or Owner icon.

I have also tried starting from last known good configuaration and it still
won't boot.

XP Home was preloaded on this machine and I do not have a startup disc.
I do have a copy of XP Pro if that might help.

Thanks, John
--
Don''t touch that knob !!!!