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Problem writing MBR for raw disk

Posted: 11. Mar 2011, 20:19
by cumthsc
I am trying to get the raw disk Win7 on a dual-boot machine running in a Fedora 14 host. I followed the instructions here, but I'm running into a problem with the final step.

I followed the instructions for fixing the MBR. Before carrying out this procedure, attempts to boot the Windows VM simply halted with the error "Missing operating system". After carrying out the procedure, the system still halts on boot with the same error. I also tried "bootsect.exe /nt60 ALL /mbr" as suggested on another page for Windows 7, but that didn't help either. Both commands claim to have correctly written the boot sector, but neither apparently does.

The only difference I can see between the instruction examples and my situation is that my Win7 partition is partition 3. The VM appears to be configured correctly, and the installation disk mounts the right partition as its E: disk.

Suggestions for getting this working appreciated.

Re: Problem writing MBR for raw disk

Posted: 19. Mar 2011, 23:12
by vbox4me2
Run the install CD as it usually has a repair mode once it detects an installation.

Re: Problem writing MBR for raw disk

Posted: 19. Mar 2011, 23:43
by cumthsc
OK I tried the automatic boot repair mode, and it failed.

The System Recovery Options pop-up lists no operating system. Selecting "Use recovery tools..." anyway and then choosing "startup repair" results in a pop-op:

Startup Repair cannot repair this computer automatically

Code: Select all

Problem details:
Problem Event Name: StartupRepairOffline
Problem Signature 01: 0.0.0.0
Problem Signature 02: 0.0.0.0
Problem Signature 03: unknown
Problem Signature 04: 0
Problem Signature 05: unknown
Problem Signature 06: 1
Problem Signature 07: unknown
OS Version: 6.1.7600.2.0.0.256.1
Locale ID: 1033
Any idea what to try next? This is a Dell Latitude E6410 laptop and the Win7 image is the one from Dell.

Re: Problem writing MBR for raw disk

Posted: 19. Mar 2011, 23:54
by vbox4me2
Try the gparted ISO to see if the correct partition is active.

Re: Problem writing MBR for raw disk

Posted: 20. Mar 2011, 00:25
by cumthsc
gparted recognizes /dev/sda3 (the right partition), and sees the rest of the partitions, but lists them all as unknown. No partition is selected as the active boot partition. If I fix that here, is it correct that it won't affect the actual partition table on the disk, so that my Linux /boot partition will still be active when I reboot the physical machine? My GRUB is installed on /boot.

Thanks.

Re: Problem writing MBR for raw disk

Posted: 20. Mar 2011, 00:45
by vbox4me2
No idea, back it up and try.

Re: Problem writing MBR for raw disk

Posted: 20. Mar 2011, 02:49
by cumthsc
Progress. Making the Win7 partition active in Vbox doesn't affect the setting on the real disk. And it does cause Windows to attempt to boot. Now it goes into an endless cycle of bluescreens and reboots. The error goes by too fast to see what it's about. Attempting to repair fails again, but with more content in the error messages. I can get that information if necessary.

Rebooting into Windows on the raw machine requires a safe-mode boot, then it works again after that.

Any ideas what else I need to fix?

Thanks for your help so far.