Getting slower all the time

I'm not sure if this is the right forum. I don't think that I have a spyware issue so I have not done a hijackthis log.

When I first got this pc it started up very quickly and now it takes quit some time. The first couple of hours it seems to be acceptable but not where it once was.

I am looking for some direction as to which forum I should really have this in and if I have to perform anything beyond the spybot search which I have already done.

I just want to see what I can do to speed this up.