With your computer problem as it gets slow, all computers do no matter what. I'm using Windows 7 64 bit, my computer has ATI Radeo 5 series card which is pretty good, 7 series is high end, 12Gb RAM, 1 TB hard drive and AMD 1100T 3.3GHz 6 core processor and it still gets slow down. If you are using Windows XP though it had been great operating system but Microsoft is going to stop 100% support of Windows XP in 2014 may be Jan or April 2014. Windows 7 is the best stable operating system.

Try to run defragmenter on your computer on regular basis. Delete temporary files. Save all your data on partitiion D: or E: not save anything on your C:\ drive where OS resides. There are many registry cleaning software available in the market. Try this one download free version and run it to your machine

http://www.piriform.com/ccleaner

Also try to keep updating your windows updates. Also you need to increase the size of your page file, if you do not know how to do it, I'd try to help you. But sorry Windows XP is gonna be history. Within $600 you can build a great machine for your home which would get you thru for another 5 years, if you need any help to build your new machine, I'd help ya. If you were in TX, I would have built the machine for you, though it's not as hard as it used to be.

Mody