I have a serious problem with a bunch of computers. They're all equiped with a ASUS P9X79 Pro Mainboard, running Windows 7 Ultimate and refuse to boot starting with one machine yesterday morning and 4 more today.
All showing the same Symptom: Reboot or Insert proper boot decvice
I got one of them and reinstalled Windows 7 Ultimate, which worked absolutely fine. Afterwards I installed the newest drivers from the ASUS website. Then I searched for Updates and after about 2 hours Windows Update told me it has found 220 new Updates. So I installed them which took me another 1.5 hours. After all the updates were installed, Windows required me to reboot to complete the process, so I restarted. Doing so resulted in a screen showing Stage 1 of 5, then 2 of 5 and so on. At Stage 5 of 5 it stalled at 32% for about 30 minutes, then rebooted. Again it showed Stage 5 of 5 but that time the percent numbers climbed rapidly to 100%. Another reboot followed, which resulted in Reboot or Insert proper boot decvice
When the first machine came up whith that problem, i expected a damaged hard drive, but now with 5 of these machines, equiped with the same type of mainboard and the same behavior I belive that one of those Windows updates killes the boot sector. Also one of the operators of one of the affected machines told me that his machine was installing updates on shutdown the evening before the problem occured.
I tried to boot from the Windows 7 Ultimate Install disk, selected Repair -> command prompt, where i hoped to fix the problem with BootRec.exe /fixmbr but with no luck. Also if I do BootRec.exe /ScanOS I get 0 found Installations.
But if I do a dir on drive C: I see the Windows installation.
Can anybody give me a hint on how to fix those installations?
Update 26.04.2016:
I've got one of the machines on my desk today and it refused to boot. After that I went to the BIOS to see that there are more boot options then in the past. The new entry is called "Windows Boot Manager". Is it possible that a windows update can create a new boot option? I know that for sure because these machines tended to loose their BIOS settings once in a while and I had to reconfigure that over the phone a few times and there was no "Windows Boot Manager" entry. This is so weird because i recognized that entry on the first machine i got back and changing the boot order to that one didn't make the machine boot. But for some unknown reason this time it worked!?
Any way, i will try to figure out which update causes this kind of Problem as suggested by @Massimo