All the above advice isn't going to help you one bit.
If you have Windows XP download, update, and
run Ad-aware
http://www.lavasoftusa.com/support/download
If you have Windows 2000/ME/98 download, update
and run Spybot
http://www.safer-networking.org/index.php?page=download
On the link freeadultcontent gave you...
http://www.spywareinfo.com/~merijn/downloads.html
...download HijackThis and CWShredder.
- boot into safe mode
- Run CWShredder first. Make sure your check for updates before
you click the Fix button.
- Reboot into safe mode
- Run HijackThis and post the log file here
I'll keep an eye on this thread for an hour. It's 22:21 PST