Updating Win OS on separate drive killed my boot

[dreambig207]

Somehow after updating windows on another drive I can't boot into my Sierra hack anymore. When I try using my USB installer I can access the installer but time machine isn't showing up so as to restore.

Any thoughts to help or a better place to post this? I figure the EFI partition has been corrupted but have no way of fixing that, I'd restore from Time Machine but without being able to access disk utility I don't know how to do that.

Thanks!

 

[Going Bald]

Somehow after updating windows on another drive I can't boot into my Sierra hack anymore. When I try using my USB installer I can access the installer but time machine isn't showing up so as to restore.

Any thoughts to help or a better place to post this? I figure the EFI partition has been corrupted but have no way of fixing that, I'd restore from Time Machine but without being able to access disk utility I don't know how to do that.

Thanks!

Try boot to UEFI/BIOS, set optimum defaults, than make same changes you made to originally install Mac OS and set the Mac OS drive as first in BBS Boot order; save&exit, continue boot