You may want to use Microsofts free anti-spyware (Looks like it's incorporated into Defender) software and CCleaner. Both excellent products.
http://www.microsoft.com/athome/security/spyware/software/default.mspx
www.ccleaner.com
"Windows Defender (Beta 2) is a free program that helps protect your computer against pop-ups, slow performance, and security threats caused by spyware and other unwanted software. It features Real-Time Protection, a monitoring system that recommends actions against spyware when it's detected, and a new streamlined interface that minimizes interruptions and helps you stay productive."