Tell me which hardware device was the lastest you added to your computer, and i would recommend you remove the 6 gb harddrive from your computer.
Let the computer be fast, dont add a bottleneck to your system like the harddrive on 6 gb, its way too old to your system.
Remove also the CD-Rom, you have a DVD burner which is alot newer then the cd-rom drive.
Let the system be fast instead of slowing it with old hardware devices.
Now test Jedi Academy Again.