Antivirus help with XP?

Antivirus got hold of my pc and disable my every thing except internet shortcut on desktop,i ran antivirus like AVG and spyware terminator with no help at all,there is window on the center of screen it said,you need to run antivirus to remove all .I don`t want to format the drive,i have so much in it,any idea how i can fix it,the problem you can not access the registry,control p or any program,they all disable