Hi I have a Windows 8 x64 64 bit installation on my laptop I screwed up the MBR and BCD while installing Ubuntu, so now I can't boot into Windows. The boot config files are missing. I can't make a recovery disc from another PC, and I have no Win8 install disc. Can I use a Windows 8 Core USB to repair windows? Do I need the .iso for Win8 Core Single Language x64 or can I use Windows 8 Core? Can someone tell me where to download w8 single language x64 .iso Also if anyone can tell me how to repair Windows boot files from Ubuntu, I appreciate it. I am currently on Ubuntu
Can you check if you have a recovery partition on your disk? If yes, I would suggest you try Fn key(depending on your laptop model) at start up to trigger system recovery. such as F11 for HP laptops.
you can use any win8 media to repair your mess. take your core usb, boot the winpe. hit shift + f10 for console (easiest way - there are many alternatives more nerdy ways) open notepad (yes notepad.exe) - this is only for gui browsing "open" locate to 'computer' look if there is some partition 100-350mb and note the assign letter, also as you should identify the letter for your broken os. now close notepad and just type: replace X: with system partition replace Y: with MSR/EFI 100-350 partition if you have one, otherwise forget the last parameter Code: bcdboot X:\windows /s Y: The letters have to be the CURRENT assigned one. Don't use guessed letters, as you think the Windows drive (in winpe) F: atm but will be C: after restart. Than just use F: For EFI you might need: bcdboot X:\windows /m {d58d10c6-df53-11dc-878f-00064f4f4e08} but I haven't tested this command.