Why can't you get adaware?
You should look at your startup programs in the start menu (of all profiles), and check the startup apps in msconfig. If you find anything you believe to be related to that spyware package (they often disguise their names, too, btw) disable it. Often, spyware launches a program on startup that sets your home page and keeps checking it and setting when required.
If you need adaware, I can email it to you.