Ok first to find out your hardware, click start, then run, type in dxdiag and click run, then on the window that opens click on save all information, save it on the desktop, open the text file thats been created from that and you should see all information about your pc.
Second, i had the game running on windows xp no prob, HOWEVER, it was strongly suggested that if you use windows xp then update the game to the latest version, so find the latest patch for the game and apply it.
Since you've been messing around with cracks and so on, i suggest you uninstall and delete the folder if left behind and do a clean install of the game.
Also, once you find out your graphics card, go to the official site and download the latest drivers, if it's a geforce or any nvidia card go to
www.nvidia.com if it's ati, radeon, rage, etc go to
www.ati.com
Also next time, contact tech support.