Hi
As a start i recommend that you download Firefox as a browser instead of your explorer (if you use explorer)..... it is Much safer.
http://www.mozilla.com/en-US/firefox/
After you downloaded Firefox i would recommend that you download the programs, update them, run a FULL scan (one program at a time) and delete the infections...
start with Ccleaner (no need to update)
http://www.ccleaner.com/download
delete everything the program finds...
This will take alot of crap from your computer and will make the next scans much faster.
Superantispyware (need an update)
http://www.superantispyware.com/superantispywarefreevspro.html
Spybot - Search & Destroy 1.5.2 (need an update)
http://www.safer-networking.org/en/download/index.html
Ad-Aware 2008 (need an update)
http://www.lavasoftusa.com/products/ad_aware_free.php
a-squared Free 3.5 (need an update)
http://www.emsisoft.com/en/software/download/
** They are all free programs **
good luck.