what you need to do is this...
1. If your using something like Spybot, it won't get everything. CounterSpy will. Get that program. Sometimes adware was unintentionally installed, but you allowed it to be, so it runs as any other installed program. You might be able to go to control panel, add remove programs, and look in there too. I know stuff like When U Save will show up there. Also run norton or mcafee. I have norton, but i like macafee, and i also have 3 spyware removal tools, 1 from norton, then i have spybot, and counterspy. Adware Removal or whatever that program is called is a great one too. Adware & Counterspy will help you out a lot. On Spybot, you'll want to get into the advanced options, and then look at your startups to see exactly what is being run when you start up your computer... BTW, it would probably be best that you first off, update and get those softwares, and then, you restart your computer, disconnect from the internet, and run windows in safe mode. Also it really doesn't matter of what type of connection you have, but I think netzero did have some spyware/adware along with it back in the day... If you do have that Adware or whatever program, run counterspy, that program works great. It will get EVERYTHING lol. However, the BEST tool to get spyware out of your system, is a clean installation of the operating system.
So step 1: Get Counterspy
2. disconnect computer & restart in safe mode
3. run virus scan & adware tools
4. check your add/remove programs
5. use spybot in advanced mode, and check the start up stuff, and also check to see if everything is blocked in there, also there's the Tea-Timer, which does not allow jack shit to run unless you press ok lol. It's kind of annoying when your trying to access your email and it pops up, but everything is ran through you before running. Norton & Mcafee has similar things.
6. I even go as far as using Yahoo's anti-spyware tool.
7. Norton is included in the Yahoo toolbar for trial (might need it installed so u can also run that tool too).
Then you SHOULD be fine.... if it still gives you problems, come post up exactly what files are popping up.