I visited a web page and there was a virus on it that changed my IE home page to an advertizing page that had a bunch of popups. it also changed something in my windows xp pro that will not let me access my registry thru the run prompt. I get a message saying registry editing has been disabled by your administrator. I am the administrator. How do I fix this? any help would be greatly appreciated.

It wasn't a virus. It was malicious code on the site that used your weak browser's holes to execute. Forget IE....it's a security flaw masquerading as a browser. Download Firefox from Mozilla.org and move on. Also download and run Adware from lavasoft.de. It'll problably get rid of the spyware you've given yourself.

Your browser has been hijacked. Download and run a problem called Spybot - Search and Destroy and it should be able to clean it up. I just cleaned a computer with it today - you may have to run it a couple times and if I were you, once your system is clean, turn off system restore then re-enable it. The spyware will still be lurking in past restore points and if you were to restore to an earlier date, the hijack will be back.

I did go to firefox, I ran spysweeper and got rid of all the adware, but I'm still locked out of regedit.

You could try to reboot in Safe Mode and see if you can get into registry that way.

no I'm locked out of the registry, sfe mode or normal mode. There has to be a way to turn the registry editing ability on and off, the hack turned it off, then i should be able to turn it on again.

Okay, try this. If system restore is turned on, try to restore your computer to a date before the malware attack (if you didn't already turn it off like me earlier suggestion). If you can restore your computer to a point before all the problems began you will be able to get into the registry again but you will need to run spybot again because even though you are turning back the clock so to speak, there could still be files on your computer that don't disappear by restoring to an earlier date.