So about a week ago I was playing Fallout 3, and while playing it crashed. No biggie, happens all the time, right? Well, not this time. After playing I restarted my computer, and it wouldn't start up. At all. It kept trying, and finally booted into Repair mode. Long story short, nothing worked. Startup repair 'couldn't repair your hard drive,' system recovery 'there was a problem and we couldn't restore your system,' or something like that. In the end, after days of troubleshooting, the only way I could get my computer back was to completely reinstall Windows.

Well, must have just been a weird fluke, right? After a painstaking process of reinstalling all my applications and restoring all my documents, just this morning I played Fallout 3 again, and again it crashed—and AGAIN it's now giving me the blue screen of death and all the 'repair' options are giving me zilch! I'm looking at reinstalling Windows and everything else yet again! Could it be a freakish coincidence? Maybe, but I'm thinking not.

I'm running WIndows 10, whatever the latest update is, on a 2017 iMac via Bootcamp. I've been running Windows that way for years with no problems until now. I played all the way through Skyrim, Fallout NV, and several other games on Steam with no issues. Fallout 3 is the first GOG title I've played, and I put about 50 hours into it before all this started happening.

Any ideas? Is there something I could do to avoid having to spend the next few days setting my Windows installation up from scratch again?

Sounds like faulty hardware. If you are lucky, just a bad cable.

If there is a piece of faulty hardware, having software that pushes the envelope a bit can make it show its fault. That's probably what happened to you.

Check disks, RAM and processor; in that order. You can do all that by software.

I'd tell you to have the power supply tested and/or exchange it temporarily with another, but that's kind of difficult with an iMac. You can still check what happens with the voltages when under load by software. There was something you could have done, but not now. Make a backup of the clean install, and then another (or a differential one over the first) after updating the OS, and yet another after installing all drivers and basic software.

Advice if you have never done a full partition backup before: Right after the first one, test if it restores properly and that you are comfortable doing it; you don't want to go through all that trouble and then have to reinstall anyway because you realize you can't use the backup.

Thanks for the help, everybody. Turns out the culprit was an external hard drive I had plugged in. I'd never even thought of that because, as I said, I've been running this setup for years with no problem, and it only started after Fallout 3 crashed (twice in a row!). The computer itself is fine, I ran some hardware tests and they all came back OK. I booted up with that particular drive unplugged, though, and it started up! I'm not sure how that was the problem, but I'm not arguing.

As for the backup of the system, another of the weird things that was happening is that I actually had one, but was unable to restore from it. I had it on another external drive (not the same one I mentioned earlier), which I had been able to read from just fine always before, but for whatever reason the system completely refused to recognize the disk when I tried to restore from it.

Anyway, thanks again, and I'm keeping my fingers crossed that the problem stays solved. And from now on if I run into problems I think the first thing I'll do is unplug everything and see if the problem goes away. ;)