My brother's W10 laptop had a boot error. No boot repair would fix it. So I lucked out. I had a Dell Inspiron of another model but figured close enough to make the 16GB USB full Windows 10 recovery USB stick. I read http://windows.microsoft.com/en-us/windows-10/create-a-recovery-drive and selected the " Back up system files to the recovery drive " option. I can't guess why but it took 4 hours to create the USB recovery drive. Yes it was some nano USB 2.0 drive but I add this so you know to set aside the time.
I did not use step 4 of the link given.
The recovery USB stick did boot but did not repair the drive. A quick check with my brother and he said go ahead with a full "reset your PC" as noted at http://windows.microsoft.com/en-us/windows-10/windows-10-recovery-options
I returned home from work yesterday to find that my computer won't boot. Great, it's going to one of those weeks... After the bios screen and the windows 10 logo, the computer hangs on the following screen, blue background with the spinning white dots. It looks like it's trying to log in, but it gets stuck. The dots never freeze- it just keeps spinning and trying to log in. Before I go further, I'll give you some specs:
Homebuilt Windows 10 desktop, up to date (upgraded from 7 months ago)
Gigabyte z87x ud3h mobo
Haswell i5-4670k
Nvidia 780ti
8gb ram
Ok, where was I. The strange part about this is that everything was working fine the other day, and I didn't really do anything since then. I upgraded from W 7 to 10 months ago and it's been working fine. There were no windows updates (Feb 22nd), and I didn't install any other driver or system updates. In fact the only things I did install were the Steam VR test and a game on steam. Nothing else was changed since the last time it booted properly.
Now, onto what I've tried. I'm at a bit of an impasse here because I can't really get the computer to do anything. Booting into bios works, but that's about it. I can't get into safe mode (thanks W10, F8/shift+F8 doesn't work, can't restart into it from desktop, or from login screen, crtl+alt+del, etc). I've messed around with cables inside the tower, plugged and unplugged hard drives. In the course of restarting many times, I got a "bios corrupt" error, after which it started recovering into the secondary bios (losing all my OC settings and other bios settings). But the problem persisted. I then tried updating my bios, but I keep getting "invalid file" messages when I try to update from bios/Qflash.
Finally, I didn't have a W10 recovery drive, but I downloaded one from Microsoft. Startup repair says it cannot find any issues, and attempting a system restore gives me the error "you must specify which windows installation to restore. Restart, select OS, then select system restore." That doesn't seem helpful. Ok, on to command prompt. Trying to enter safe mode from here gives me a "boot config data could not be opened. System device not found." CHKDSK /r also returns an error. Then I tried to rebuild the master boot record (as detailed here How To Use Command Prompt To Fix Issues With Your PC's Boot Records) with no luck. All of these issues seem to point to the hard drive or OS on the drive not being recognized. Yet the drive does show up in BIOS, so I don't think it's hardware related. Regardless, after work I will try to attach the SSD to a working computer.
Anyway, I think this sums things up. Let me know if you need any more info, or if you have any ideas on how to continue from here. Is there anything else I can do in the command prompt? Thank you very much.

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