I presume your refering to BSOD on boot INNACCESSIBLE_BOOT_DEVICE
heres the fix
On occasion, the user may wish to exchange the mainboard of a computer system running Windows 2000. Unless the replacement is identical to the original, a STOP (Blue Screen) error INACESSIBLE_BOOT_DEVICE will be observed when attempting to boot the existing disk image on the new board. This is caused by the presence of a mass storage controller on the new board that is incompatible with that on the previous motherboard. In most cases, this scenario will require a re-installation of Windows 2000; however, there are instances where this is not necessary, if the following conditions are met:
The Mass Storage Controller on both the old and new boards are standard onboard ATA/IDE PCI devices, as commonly found on many desktop system boards.
Neither controller uses RAID functionality.
It is still possible to boot Windows 2000 on the previous motherboard.
If these conditions are met, then the user may wish to try the following procedure:
1) Boot the PC system using the existing (previous) motherboard. **If you've installed the UltraATA Driver (if so, Device Manager->IDE Controllers->Primary Channel will be lacking its usual "Advanced Settings" tab) then uninstall said driver from Control Panel and reboot before continuing **
2) From the Device Manager, open up the "IDE ATA/ATAPI Controllers" section. On a typical system there will be three entries under this - the controller itself, and then the primary/secondary IDE channels.
3) Double-click on the entry for the controller, and change the driver to the generic default Microsoft "Standard Dual-Channel PCI IDE Controller". This is to IDE controllers what the Standard VGA driver is to video cards - i.e., it'll work on just about anything, but is rather slow and basic.
Note: If you're going to change graphics adapters as part of the motherboard change, be sure to change your graphics adapter driver to Standard VGA before you shut down the old motherboard for the last time. Otherwise, the computer will try to use the wrong (old) driver for the new video card when you start up.
4) Now shut down the system, and replace the motherboard as required.
5) If the new IDE controller is compatible with the "Standard Dual-Channel PCI IDE Controller" driver, then the system should boot into Windows 2000. (The "generic" driver is compatible with most IDE controllers out there - albeit at lower performance.)
6) At this point you should install the correct optimized IDE/ATAPI drivers for the controller. (i.e. VIA 4in1 drivers).
good luck