I seen this posted earlier and now I am having the same problem:
I noticed the Primary and secondary Controllers has a yellow exclamation point under device manager/hard disk controllers. Also the cdrom is not listed. The machine shows it is running in Protected Mode. All Microsoft’s Critical Updates have been installed on this machine also.
I have tried deleting the controllers and rebooting. The controllers are reinstalled only to have the exclamation points still there. Please let me know if more info is needed. Thanks.