After installing service pack 3 my computer went into a endless cycle of restarting. I had to do a hard shut down and re-start in safe mode, then restore my computer to a previous date to get the computer to work. Thinking it was one time issue I tried it again with the same results. Is this a problem with the service pack or my computer. Also, my computer won't download anything now.

Did you have the Service Pak 2 installed on your computer prior to adding the Service Pak 3? That might be your problem.

What brand and model of computer do you have?

It's an HP Pavilon. I usually don't pay much attention to the updates from Microsoft, I just download them. I only noticed this one because of the adverse effect it had on my computer. As far as service pack 2, I can't give a definite answer. I may have downloaded it with another update. It's probably obvious, but I'm not very computer savvy. Thanks for help

You definitely would have noticed the Service Pak 2 as it was very large. I had to get a disc version of it because I had dial up and it would never finish downloading. Trust me, you would have noticed it,

It's an HP Pavilon.

There is a known issue with HP's hard drive imaging, the Intel power management driver, and Windows XP Service Pack 3 on AMD based HP computers. If your computer model is AMD based, see Computer Restarts after Displaying Stop Error 0x0000007E (After Updating with Service Pack 3 for Windows XP) (http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&dlc=en&cc=us&docname=c01457284).