Hello there, I have a problem using two operating systems on different partitions of my hard disk, My system spec are: OS Version: WINDOWS VISTA ULTIMATE 64 BIT Intel Pentium D 3.0 GHz 945 GNTL Motherboard Corsair XMS2 (DDR2) 512x2 = 1 GB Ram XFX 8600 GT XXX Edition 256 MB (NVidia 8600GT) with latest drivers 158.xx Western Digital 160 GB SATA 2 Creative Audigy Sound Card with latest available drivers Location: PAKISTAN Problem: I am basically a medium level software designer. My softwares are not running currently on WINDOWS VISTA. So i plan to install Windows XP and Windows Vista Ultimate 64 bit both on different partitions. And i do the same on my "C" drive i install WINDOWS XP SERVICE PACK 2 after installing important software and drivers i install WINDOWS VISTA ULTIMATE 64 BIT EDITION on my hard disk's 2nd drive "D". but amazingly when i install my 3D Card (8600 GT) drivers. my 3D Card is not working. i try both ways to install the drivers 1. By install the exe file provided by the company. 2. By using DEVICE MANAGER and browse for driver on my hard drive. but failed. but when i install WINDOWS VISTA ULTIMATE 64 BIT EDITION alone without WINDOWS XP. it works fine every thing is working just fine. i plan to rebuild my personal softwares to use with both WINDOWS XP & WINDOWS VISTA but with this mentioned problem, it is very difficult for me to rebuild them again. I am facing great difficulties. please solve my problem as soon as possible.