Hi all! I don´t understand the problem and can´t find any solution around the net.. I have a first gen. macpro and a native 7300GT in it. I had a bootcamp partition under Tiger, 32 Go Fat 32 everything worked fine. I upgraded the system to Leo, kept my bootcamp partition from Tiger everything worked fine. Now I decided to get more space for XP, deleted this bootcamp partition and made a new one, more than 100 Go NTFS under Leo. After installing XP and the drivers from the Leo DVD, Direct 3d refuse to work. I tried everything, installing XP again, uninstall nvidia drivers and install new one from Guru (170..), install very old ones (91..), unplug the card, change VGA/DVI, nothing to do, the card works but no Direct 3D. Some opengl application work, but if you go under nvidia propeties pannel, the first window where you can choose between speed and quality with the rotation Nvidia logo, it is grey, no 3D logo, nothing. edit. found my old tiger driver CD, uninstall everything (driver cleaner pro) and install from it. But it didn´t change anything.. looks like a hardware problem, but the card works fine.. don´t know what to try next. Thanks for your help.