You are paying that much to keep getting it fixed ? Good grief ...
http://www.free-av.co...ir_rescue_system.html is free. Download, burn to a CD or DVD, boot from the disk and run the AV scan.
When it's cleaned up, check for malware with either Malwarebytes or Superantispyware (or both, and don't forget to get the latest updates before running a scan), then use either GMER (www.gnmer.net) or A Squared free (http://www.emsisoft.com/en/software/free/) to check for and remove any rootkits.
Then think about using OpenDNS as your DNS service - that will block you from going to a lot of sites which automatically install malware on your machine. You have to sign up for it, bit it is free and there are instructions on the site to tell you how to set everything up (including wireless routers).
Finally, if you are running XP, download Tweakui and use it to disable autorun (that should take care of infections from CDs/DVDs/USB sticks that people lend or give you things on. Sorry I don't know of a convenient way to do it in Vista.
You won't be 100% protected with all that lot done, but you will be more protected than you seem to be now