i have a compaq presario s6000cl, it has 512mg of ram, 80gb hard drive with an athlon 2.08ghz processor. the computer is 3 years old and it has slowed down alot, like it's cluttered up or something. i don't have a great deal of knowledge about these things but i have defragged, disk cleanup and have an antivirus program. i don't want to lay down a bunch of cash for a new computer but i'm willing to spend some money to upgrade this one so it would last a while longer. what are the best things i can do to help this thing out? thanks.