Please Help! game crashes for no reason

[live2004]

Please, anybody whp thinks they can help me please reply. My NBA Live 2004 game is always choppy no matter what screen it is on and it can freeze at any moment, making me have to restart my computer. I have 1.3 GHrtz hard drive 256 DDR Ram and RADEON 8500 graphics card. I have defragmented my disk and checked for errors numerous times. Last night I tried to copy all the files from both cds on to my hard drive, but I cant get it right (it keeps asking me if I want to replace certain files. I am only doing this with hope that it my run faster. If anyone can help that would be greatly appreciated.