Hi Mike13

Most people are familiar with freeware, shareware, cookies, media players, interactive content, and file sharing. What they may not realize is that some of them actually collect and disseminate information about those using them. They can track your surfing habits, abuse your Internet connection by sending this data to a third party, profile your shopping preferences, hijack your browser start page or pages, alter important system files, Add additional popups to WebPages and they can do this without your knowledge or permission. The security and privacy implications of these exploits should be quite obvious and undesirable on any system or network!

You should check for spyware that may have hijacked your browser and could be using valuable bandwidth and has attached itself to the windows operating system. These things can send you email Spam and also send you additional popups at every web page you visit.
You can download a program called "ad-aware". This is a free program that will detect 1000's of web tracking spy software that may have found a way on to your computer by using strange tricks. You may get it from here,

http://www.lavasoftusa.com/software/adaware/

download,
http://www.lavasoftusa.com/support/download/

These things really mess up Internet Explorer and crash your computer all the time.

You should delete everything it detects.
cheers egghead