Hard drive speed slowing me down

I seem to have some speed issues...I am going to assume have to be harddrive related.
I looked at the performance information in windows 7, it is indicating 7.3 to 7.5 for everything but data transfer rate which is a 5.9. I am running windows 7 (which in it self has issues).

The hard drive I am running the OS on is a WD 640GB drive #wd6401aals, all the data storage is on another drive to keep this one freed up.

side note, I am running a amd quadcore 3.2 ghz, 8 gig of ram, gigabit board and a radion 4800 (this is coming out soon)

I am looking for faster app launch and internet speed.....also if I dont reboot for several days my speed degrades cinsiderably by almost 2 seconds between application launch to even my typing in word or on the web will be several letters behind, I will have to wait for it to catch up.