Do you have a backup?
If yes, re-install the OS and restore from this backup.
If this does not help, refer to that: http://support.microsoft.com/kb/927391
Also, please check your disks cables.
- Marked as answer by MumthazMuhsin1 Wednesday, August 24, 2011 11:26 AM
if you can verify the Boot Configuration in your Bios and make sure that you select the right boot drive , and you can use this links it can you to resolve this error:
Oussama Oueslati | System Engineer | vNext Consulting