You offer nothing is what the malware maybe, provide what you do know as best as possible.
I suggest you visit the "spyware,virus and security" forum and check the 1st sticky, etc. and follow the guide and/or get pgms. Post queries there as more knowledgeable users visit there on this topic, that could help you. Of course, you may need to use another PC, burn those pgms. in order to use later. I suggest also, visit the McAfee website and get the "stinger" pgm. to detect common malware. Next, you can load or boot-up into "safe mode" as a precaution to help run those AV pgms. etc.. if you're online with this PC posting your message, visit an online scanner website that could help as well. Allow them to detect and remove what they find.
Beware, even if you gain some success, you maybe better served by simply wiping out your HD and reloading the system to be as safe as possible from this attack. Of course, that's up to you and the results of any malware removal.
Seems I have contracted either a virus or spyware that is not allowing me to do anything on my computer unless I agree to dowmload the virus scan. It infects all of my .exe files...Help? I can't seem to get it removed. I am running vista on a homemade system.