I have a dual boot setup (Win2000 and WinXP), working fine until I tried to install drivers for a Rosewill PCI SATA adapter (RC-215). After that every boot(Win2000) gave me an error message that said windows/system32/SYSTEM was missing or corrupt. My WInXP boot was working ok until later that week, when it failed also. The SYSTEM file wasn't missing, I tried a different one from another Win2000 installation but that just gave me an error message about " load needed dlls for kernel"...so I'm guessing the SYSTEM file is particular to a given installation. I have Hiren's Boot CD 15.2 which gives me access to the hard drives...everything tests ok, and I've tried a checkMBR program which tells me that it recognizes a valid WinXP boot setup, but says nothing about the Win2000 boot setup I'm also seeing some weirdness in Drive Management, the order of the partitions(boxes) is changed a bit. Looking in Boot.ini, things look normal also I'm not sure about the partition number listed for the second boot. I need some basic troubleshooting information for this kind of situation. I'm reluctant to rebuild the MBR without knowing more. Can someone help with this?