Need Help Restoring EFI and MSR Partitions

Streblo · 09 Nov 2016

Hello,

I think that for some reason, my EFI and MSR partitions were not located on my main Windows drive.

When I installed linux mint on a separate drive, Windows refused to boot. I did the usual linux chain of debugging like boot-repair and update-grub but I don't think that's where the problem is.

Upon investigation in both linux and diskpart on a recovery cd, my Windows HDD is missing a EFI partition and a MSR partition. It only has the main data partition and a recovery partition. Even more interesting, there is no unallocated space on the Windows Drive so the EFI and MSR must have been somewhere else. I believe the EFI and MSR were on the drive I installed Linux to for some reason, and they were overwritten.

My plan now is to format the recovery partition and put an EFI and MSR partition there and then restore using start up repair.

I need to know if

a) this will work? (EFI and MSR won't be at the beginning of the disk) and
b) how big do I need to make the partitions for 64bit windows?

Thanks.

dalchina · 09 Nov 2016

Hi, one way to get all your partitions on one disk is to use e.g. Macrium Reflect (free) disk imaging.

In outline- and posted in more detail elsewhere on the site (which you're free to search for) is
a. create a disk image of your C: partition.
b. clear enough space on your system disk.
c. Clean install Windows on that disk.
d. Restore your image of C: in place of the new Windows partition created by the installation.
e. Run Startup Repair.

As in any such action, create appropriate backups before starting.

NavyLCDR · 09 Nov 2016

What @dalchina posted +1

Saltgrass · 09 Nov 2016

An MSR partition is associated with a GPT configured drive, so make sure the one you want to put an EFI partition on is GPT. I have seen a system with the EFI partition after the OS partition.

The current EFI partition, if your system has one, should be visible in disk Management. If you don't show one your install may not be UEFI.

dalchina · 09 Nov 2016

You could post a screenshot of Disk Management before starting- and preferably one using a 3rd party partition manager such as Minitool Partition Wizard as the 16 Mb System partition isn't shown by the former. Also check whether your PC supports UEFI or not.