Windows 10 not found, no boot from SSD, MBR error 1/no operating system found error

[rorkesdrift]

Here is what happened:
1. Tried to install XP 64 bit on an HDD that wasn't doing much else. Told me it needed to write files to C: before it could install on the one I wanted, so I turned everything off, unplugged all HDDs (and SSD) except the 1 that I wanted XP on. Installation worked fine (although I don't have a working key, alas).

2. When I plugged SSD back in, got error no OS found. Checked all cables, they're fine. Tried different cables, nope. Tried to boot from HDD that still has windows 7 on it, got MBR error 1, then error 2.

3. Drives show up in BIOS, so it doesn't seem a hardware issue. Booted to Linux (Mint 17.3) CD and tried to access my other drives. SSD is in "unsafe state," with Linux suggesting that windows 10 was in hibernation and failed to turn off completely. Independent research on my part seems to indicate that the boot files have been adversely affected by my unplugging the SSD while windows 10 was hibernating (woops!). SSD is currently unmountable except in read-only mode.

4. I can, however, access the files on the HDD with windows 7 on it (although I cannot boot from it).

My issue is thus two-fold. A) how can I repair my windows 10? and B) why can't I just boot into windows 7?

SYSTEM:
AMD Phenom II X6 1055t 2.8ghz
Gigabyte 890gpa-ud3h
8 gb DDR3
ATI 7850 GPU
Samsung SSd 840 pro 128gb

 

[Lutfij]

If you can get into the troubleshooting screen you can try and perform an sfc / scannow or a system restore prior to when the issue occurred. You can also follow up on this article or this article and see if it alleviates your issue.

While we're on this topic of maintenance, are you sure your BIOS and drivers are up to date? Is this installation of Windows 10 based off the free upgrade path or anew?