Some of the suggestions already posted will help you identify the application that is causing the problem.
1) Hitting Ctr-Alt-Del will bring up Task manager and click on the "processes" tab. Sort on memory, descending and see if there is anything using a lot of memory, do the same using the cpu column. If you see anything do a google search on the name listed and see what comes up.
2) If that doesn't solve it download and run "process viewer". It is freeware that will show everything running and what other apps it they are related to. If anything seems suspicious such as "Bargain Buddy" for example, do a google search on it to ensure it is not important and then find a way to get rid of it. I mentioned "bargain buddy" because I had a similar problem and I was able to trace the problem to it. Getting rid of it, however, was a whole other thing. It took two days to figure out how to get rid of it. A file was starting up every time I rebooted that re-spawned it. The next step is how I was able to get rid of it.
3) Download and run "Hijack This". It is freeware and will create a text file listing everything that starts up when you boot your computer. There are many forums where you can post the results and people will help you wade through the list and identify possible culprits. Someone here offered to look through it for you and I could as well.
4) Any anti-spyware program will eliminate a good amount of spyware but not all, that is why it is important to use more than one. And even if it says it removed something, it may not get all of it and it can re-spawn itself.
5) One additional method is to use "selective startup" or MSConfig to disable certain programs, processes, or services at startup to identify the culprit. An explanation can be found here. It requires some understanding of what the items are but is a very useful tool.
Good luck.
Thank you all for your help and support. I have tried pretty much all the things you suggested and didn't really find much.
However, when I turned off Zone Alarm and set my browser to it's default settings, it now runs like it's supposed to, with lightning speed. Apparently, Zone Alarm had something going on that caused the internet to slow down, because when I turned it back on to test if that was it, my browser slowed down again and I experienced the same problems. So, it's off now and I'm using just my Windows Firewall. I hope that's enough...for now.
Thanx again all. :)