How to make GPT volume bootable

[PrettyStupid]

I'm not sure the history is too helpful as the question says it all, but here it is.

On an Acer predator G3-605 running Windows 8.1 I had a mSATA 60GB SSD as system disk that was too small. I bought a larger replacement and used Acronis True Image 2019 to clone it. The clone was successful in that the files all appear to be copied, but when examined using Disk Management I see that the disk is not shown as Bootable. I have tried a Windows repair startup but that failed and produced the attached log file.

Although I am certain that I at no time cloned from larger disk to smaller, neither disk now is bootable ! And the (O&O) image I took before I started this also, when used to restore from, produces a disk that is not bootable. Baffled.

Reinstalling Windows then restoring all documents and reinstalling all programs is clearly one way forward, but I just want something like DISKPART ACTIVE that would remedy the problem. I don't know enough to know why there is no such command (as far as I know) for GPT disks.

 

[Asagrim]

Have you tried booting your windows installation media with the original drive inside, selecting "repair your computer" then using:

bootrec /fixmbr
bootrec /fixboot
bootrec /rebuildbcd

?