Howdy..
It is natural for computers to slow down after awhile..But here is somthings you can do to speed them up again
Dowload cleanup from below and use it and reboot.
www.stevengould.org - Download and Installation
Then download diskeeper and run it twice on all yer partitions
|MG| Diskeeper Lite 7.0 Build 418
Post back and tell us if it is still going slow