Antivir - SB does not detect to remove

early this morning, I got this popup( now won't stop showing different issues) on my desktop that said I had various types of viruses or malwares. Also now, I get this message that "This website is harmful to your computer" no matter what site I go to. The message also gives me an option to fix it; when I mistakedly clicked on it , it downloaded an antivirus type program that I stopped in the middle of finishing the download, but it still act like it is active. It does not show up as a program to uninstall. I deleted the desktop shortcut,and it said to delete the program I must go through the programs uninstall section of my control panel; but it doesn't show there. Now, every website I try to go to the warning message that this page is harmful shows, it gives you an option to proceed unprotected. When you click on that it leads you to a blank screen that the address is long starting with "http://ad...." I have run SpyBot but it doesn't show up as my PC having any malware on it. Please help me. Also my PC has been slowing down to freezing, to where I have to refresh frequently. could this be related?

Hi dragonsnap,

Please see this forum's FAQ which details how to produce a HJT log and copy paste it into a new topic.
"BEFORE you POST"(READ this Procedure BEFORE Requesting Assistance)

If HJT won't run please start a new topic anyway, make note of the situation and and a volunteer analyst will advise you when available.

Best regards. :)