My cousin is currently having problems on his Dell desktop. It seems more and more lately that when he boots his pc up, he will login to one of the user names on his pc, and as windows is loading the personal settings, it will just randomly restart then boot up and stay on for a while, anyone have any idea? any help is appreciated

This is a common problem with Windows XP (Home and Pro)
try booting in to safe mode, (on boot hit F8) it should bring up a prompt, if you are able to log in, there google it but in propertys you can set it not to reboot on blue screen, when you log in normaly it will blue screen and you will have an error messege to google, secondly, (did you just install something?
if you are able to log in to safe mode, chances are it is a driver problem. and you need to remove the offendig device.

sory for the spelling.

im not too sure if he installed anything lately, but the blue screen does come up, but we cant seem to figure out why, no new hardware had been installed on the pc

Get the error code and look it up on Google or Microsoft's website.

When you startup the system, press F8 to open advance startup options, select disable automatically restart option .. Then it'll not restart automatically on error. If blue screen of death comes, tell us the error code.

1) was it an upgrade?
2) only with one user account?
3) do you get blue screen error?