xcopsgen said what I was about to.

But I would also recommend you Defrag you computer, atleast once a month.
If you have windows XP click
Start>Programs>Accessories>System Tools>Disk Defragmenter

or run "%SystemRoot%\System32\dfrg.msc" same thing

you want to defrag you main drive/partition if you have multiple, most likely

C: drive.

Do this once a month to improve speed of your computer.

Also you might want to run check for spyware/malaware on a regular basis to make

sure nothing else is hogging your system memory.