How to make recovered windows partitions bootable?

Solution 1:

Windows ties its boot mode to its partition table type: Windows boots from MBR disks only in BIOS mode and from GPT disks only in EFI mode. Thus, to boot from your disk as it is now, you must install an EFI-mode boot loader. This also means that your computer must have EFI firmware (as do most machines introduced since mid-2011). Here's a blog post that describes how to do the conversion:

http://sdnalloh.com/converting-win7-from-mbr-to-gpt/

Most of that is already done (or moot) in your case; you really need to do only the stuff on the second half or so of the second page.

Alternatively, you could do an in-place GPT-to-MBR conversion and recover in a traditional BIOS/MBR way. This might be the better way to go if you've got an older BIOS-based computer; but if you need GPT because the disk is bigger than 2TiB, this would be a poor option.