I'm not sure anymore where I got that Windows Security Update code. I've been working on this for months. I now have five NASCAR 2000 games and non of them will play on any of my three computers. They all have XP and are all up to date on updates. The last NASCAR 2000 disc that worked, stopped working after one of the windows updates, but I don't know which one. I'll try to find where I got that security code and get back to you ASAP. Thanks