Software that won't remove and crashing programs

Awhile ago I been getting these weird softwares from the internet like Home Search Assistant or Search Extender, I tried running Adware but it kept crashing it only Spy-bot works. When i try to uninstall it, it keeps show up this stupid page where i have to submit a form to uninstall i been doing this over and over. Its drive me nuts becasue its crashing my instant messaging program and as well as my video player, my interent explorer has been going to the home search assistant homepage, everytime i change my homepage it goes back to that default page. I have no clue on what to do now , I just want to know how to get rid of these stupid software