Am I being hijacked?

Hi, I am running WindowsXP and keep my pc scanned daily with AVG. I have had no virus alerts from scanning for some time. I always get a load of spyware when I scan but I clear this daily and don't think it is the problem. What it feels like is that my connection is being hijacked. At times my browsing is ok but at other times it is is much slower or crashes. During some browsing sessions I get run time errors regularly and at other times I get none. I use Outlook for my email and nearly all the time now it is slow. Often it hangs when opening an email or attempting to access an attachment. It did occur to me that a virus scan or some conflict might be slowing it down but I can't find a problem myself. I know my pc fairly well and it just seems like something is draining the life out of it at times. Can anyone help or offer advice on how I can make further checks myself? Thanks

Hi sorry to hear of the problems with your machine.
If you think that its possible you have picked up an infection then its best to go here
http://forums.whatthetech.com/Welcome_New_…ers_t34502.html
otherwise
It might be wise to go here:
http://www.pcpitstop.com/pcpitstop/default.asp
and run the full tests
If you need help with interpreting the results you can post the Tech Express link here.
The tests are free and you will need to register ( which is also free and accept an Active X that is also considered to be safe from that site.
Regards
paws