Sounds like you need someone local w/hands on to do some cleaning & tweaking for you. no neighborhood geeks nearby, or any computer savvy neighbors?

My parents pc has slowed down a lot and i haven't had time to do the deep digging to figure that out yet, also my aunts laptop is slow too, it just takes so much time to accomplish anything on those machines, so I know how frustrating it can be.

some basic things you can try -
Remove any programs you don't use.
Run Disk clean up & then defrag the hard drive

Reboot and see if that helps at all.