Go to add/Remove programs and check and see if you have any of the following programs.
Remove them if present. These programs are known to be packaged with or are adware/spyware/malware:
* Alexa Toolbar http://www.spywareguide.com/product_show.php?id=418
* Bargain Buddy http://www.spy-bot.net/BargainBuddy.asp
* Bonzi Buddy http://www.spywareguide.com/product_show.php?id=512
* Comet Cursor http://www.spywareguide.com/product_show.php?id=428
* Date Manager http://www.spywareguide.com/product_show.php?id=741
* Download Accelerator Plus (Free version)
removal instructions: http://articles.networktechs.com/429-p1.php
* Hotbar http://www.spywareguide.com/product_show.php?id=481
* Huntbar http://www.spywareguide.com/product_show.php?id=426
* Kazaa http://www.pchell.com/support/kazaa.shtml
* Memory Meter http://www.spywareguide.com/product_show.php?id=520
* My Search Bar http://www.spywareguide.com/product_show.php?id=490
* New.Net or NewDotNet http://www.spywareguide.com/product_show.php?id=417
* SearchSquire http://www.spywareguide.com/product_show.php?id=584
* SideFind or IS Technologies SideFind http://www.kephyr.com/spywarescanner/library/sidefind/index.phtml
* Smiley Central http://www.pchell.com/support/smileycentral.shtml
* Weatherbug http://www.pchell.com/support/weatherbug.shtml
* WebHancer or WEBHANCER AGENT http://www.spywareguide.com/product_show.php?id=26
* WebSearch Toolbar http://www.kephyr.com/spywarescanner/library/websearchtoolbar/index.phtml
* WildTangent http://support.wildgames.com/uninstall.html
* Winad http://www.2-spyware.com/remove-winad.html
* Windows Adtools or Wind Updates http://www.spywareguide.com/product_show.php?id=1068
* Windows SyncroAd or SyncroAd http://www.spywareguide.com/product_show.php?id=979
polonus
Some specific removal tools: http://www.smokey-services.eu/forum/viewtopic.php?f=62&t=2026