OK, here's the deal. We need info about your system - computer make/model, processor, RAM, operating system, etc.
You need to make sure your system is clean. You need to get AdAware, Spybot, CCleaner, and AVG antivirus (all free just google for them) to make sure. If you can't download on this machine then have someone do it and burn to a CD for you to install.
Then we need to know about your system. How long has it been this way? What kind of spyware, etc. scanners were you using on a REGULAR basis? What happened prior to this? Do you have a legal Windows CD in case you need to reinstall? Your level of expertise? What you think may have happened? Your ISP? Your means of connecting to the internet, etc.
So give us some info so we can help you.