Hijacked Internet Explorer Home page

My home page has been Hijacked by an Adware advertisement. on booting three Icons are placed on my desk top and IE opens automatically and start launching connections to various sites selling Antivirus,Spyware and Adware remover. This happens continuosly while the PC is on ans SLOWS DOWN the machine with Fake warnings that the machine is infected with win32.netsky. Norton 2007 Internet suite was installed and it could not detect the cause. Norton 360 is now on the PC and the fault still exist. I’ve been in the registry and and remove alot of stuff which still didnot help I’ve installed a startup monitor which don’t even detect it during startup but I know it is in start up somewhere.

Any Idea about a fix. ???

Thanks