Computer automatically restarts at login window?

My computer automatically shuts off on restarts once login screen shows up what can I do to fix it I already went in to safe mode and did registry scan and also a virus and adware scan what can i do I hav a hp pavillion xt953 windows xp home edition

Computer automatically restarts at login window?

uninstall all new softwares you you had installed .

if it does not work , uninstall and reinstall all drivers .

Computer automatically restarts at login window?antivirus downloads

I believe you have a bad driver trying to load. Either that or a bad startup program. You should boot your machine and press F8 and select SAFE MODE. Once Windows starts in SAFE MODE go to

START | RUN | msconfig

Go to the STARTUP tab and uncheck everything. Reboot.

This time, do not go into SAFE MODE. If it boots into windows, you have a bad program trying to start. Run each program that was in the startup until one fails. Then you can fix that program by reinstalling it.

If not, you have a bad driver. In this case you should boot into SAFE MODE again and remove one piece of hardware at a time in Device Manager and reboot until you find the bad one.
What's causing it to do that is a Systems Crash at startup...so you're stuck in the endless cycle of bootup, crash, reboot, crash and so on...