That Chaintech mobo of yours has an NVIDIA nForce 2 chipset. They arent the most sophisticated boards in terms of features, but they tend to be stable with good performance.
To get the chipset driver go here: www.nvidia.com
click on the download drivers link and then click on platform/nForce drivers and then select nForce 1/2.
After you update the chipset driver, go to ATIs website and get a new video driver.
Then scan for spyware using Windows Defender, Lavasoft Ad-Aware SE and Spybot Search & Destroy.
Get CCleaner at www.ccleaner.com
CCleaner used to be called Crap Cleaner and it is, IMHO, the best system cleanup tool. It is free and has no spyware or adware. Run this and then defragment your hard disk. That should fix your issues!
If you have the time, go to www.sysinternals
and get Page Defrag. This program defrags your paging file (aka swap file) and your registry hives, something the MS defrag program won't do. The result is a MASSIVE perormance boost if you happened to have these files fragmented. The program has no installer, just unzip and dump the files in your windows folder and run the exe and tell it to defrag.