Simple to fix.
First, on another computer, download RKill
and put it on a thumbdrive. (keep that thumbdrive for possible future use). You need RKill because this will be loaded as a service even if you start in safe mode.
Now that you have that, restart the infected computer in safe mode by tapping F8 through the reboot process. Do Safe Mode with Networking.
Once this loads up, you may see the Antispyware trojan making some noise. Put in the thumbdrive, open it and run rkill. This may take a few minutes, but it will open up Notepad when it's done.
Next, open your browser and go to: http://www.malwarebytes.org/
Download the free version and run it. If you get any errors about being unable to connect to the Internet, let me know what browser you're using and we'll talk through disabling the proxy server.
Let this thing run, doing a full scan. It will likely find 4-6 pieces of Malware over the course of and hour or and hour and a half. When it's done, remove the malware if prompted and reboot.
Once your computer has rebooted again, run rkill again (just for fun) and do another complete scan with Malwarebytes. It should be fixed now.
There is a remnant in some variants that is not in the MWB library but *is* in MSSE, so you can substitute Malwarebytes for MS Security Essentials if you prefer.
Incidentally, the cause of this (and many other forms of) virus is because of an exploit in Flash. So make absolutely sure you have Flash and Java updated. If you ever get prompted for updates to Flash or Java, do not ignore them.
Most people ignore them as a nuisance, but they're actually the biggest hole for non-open port infections.
If you use a good browser, have one AV app running and keep both updated you will be generally very safe.