Four-step recovery:
1. Try running msconfig (Start->Run...->msconfig.exe). Select the "Startup" tab when the program comes up. What is displayed are all of the programs and services that run automatically 'behind your back' when you start up your computer. Uncheck everything that looks even remotely suspicious or unnecessary (like anything from Real Networks), then restart your computer. If something really obvious is missing, like your taskbar, you can run msconfig again and turn that service back on.
By the way, this is also a great way to speed up your computer.
2. Download & install ZoneAlarm firewall. You can download it for free from hundreds of sites on the web. I usually get my utilities from
www.zdnet.com. Once ZoneAlarm is running, you'll start getting all sorts of requests for access to the Internet, from hidden programs you never heard of. I suggest saying "No" when ZoneAlarm prompts you to let the programs through. Eventually you will learn which ones need Internet access (like your browser and email programs), and you can tell ZoneAlarm to let them through without asking every time.
3. Run an up-to-date virus scanning program. McAfee has a free one called FreeScan at us.mcafee.com/root/mfs/default.asp?cid=9059.
4. Use the Control Panel to remove any popup blocking utilities you may have and install the Google toolbar (toolbar.google.com). Google combines a killer search tool with a killer popup blocker and more, all on your browser's toolbar.
If your problems persist, system files may be compromised in which case you will need to boot from a floppy and reinstall Windows.