Fix Windows 8 bootloader after converting MBR disc to GPT
I bought a new MoBo, processor, and some 3TB HDDs last week and am currently setting up a clean installation of Windows 8 on the machine.
The MoBo is an Asus RoG Maximus VII Ranger (What?! It was decently-priced. And shiny. o.o) with the on-board Intel Rapid Storage Tech semi-hardware-RAID thingy. I've configured a RAID5 array with three of the 3TB disks (I'm already aware that a three-disk array with large drives isn't ideal, but I plan to rectify that later by expanding the array).
Windows 8 installed successfully on the resulting 5.4TB array (on the third attempt… >:/) using an MBR partitioning table. Once the machine was running and I'd installed all the hardware drivers for networking, etc, on it, I used AOMEI Partition Assistant to convert the disk to use GPT. This succeeded, and upon rebooting the UEFI bootloader throws an error complaining that a required device is missing, which I expected.
I'm currently booted to the Windows 8 Install DVD in order to fix the problem. After loading the IRST RAID driver, I used diskpart
to list the volumes on disk 0, which correctly showed the 350MB boot partition created by the installer, and my 5.4TB C:\ partition.
When I run bootrec /scanos
, it gives the following output:
Successfully scanned Windows installations.
Total identified Windows installations: 1
[1] C:\Windows
The operation completed successfully.
However, when I run bootrec /fixboot
, I receive this error:
The system cannot find the path specified.
I get the same error from bootrec /rebuildbcd
.
What am I doing wrong?
Solution 1:
You need to split the 350MB MBR boot partition into the System and Reserved partitions used by the Windows GPT boot system.
Based on instructions I wrote last time I did this process:
Load a command prompt from the DVD (Repair Your Computer -> Troubleshoot -> Advanced options -> Command prompt)
diskpart
select disk 0
list partition # To verify layout
Partition ### Type Size Offset
------------- ---------------- ------- -------
Partition 1 Primary 350 MB 1024 KB
Partition 2 Primary 126 GB 350 MB
select partition 2
assign letter=C
select partition 1
delete partition
create partition EFI size=100 offset=1
format quick fs=fat32 label="System"
assign letter=S
create partition msr size=128 offset=103424
list partition
Partition ### Type Size Offset
------------- ---------------- ------- -------
Partition 1 System 100 MB 1024 KB
Partition 3 Reserved 128 MB 101 MB
Partition 2 Primary 126 GB 350 MB
exit
bcdboot c:\windows /s s: /f UEFI
Now reboot. Hit the BIOS and enable UEFI booting. Hopefully Windows will now load.