Can't boot computer, blinking underline, all hdds detected in bios

[whosemans]

I performed a hard shut down during a Windows update since I've done it before to revert the update since they take so long but this time it backfired. Now I can't turn my computer back on because it gets stuck on a black screen with a blinking underline. It's likely that my hdd's boot function broke but I want to try everything that I can to fix it before I make any final decisions. I'm not sure if this is useful information but my hdd is still detected by the bios and my mobo can run a diagnostic that tells me that there is nothing wrong with my hdds. I don't have any backups as well. I would GREATLY appreciate any help as this hdd does have quite a few documents I would prefer not trying to obtain again.

 

[Colif]

i haven't seen this for a while, wish I could remember a solution

On another PC, download the Windows 10 media creation tool and use it to make a win 10 installer on USB << its a handy boot drive if nothing else

you can also use this to copy files onto other hdd if it helps: http://www.howtogeek.com/howto/windows-vista/use-ubuntu-live-cd-to-backup-files-from-your-dead-windows-computer/

I would see if this helps:
boot from installer, on 2nd screen after languages, choose repair this pc, not install
choose troubleshoot
choose advanced
choose command prompt
start from step 4: http://www.thewindowsclub.com/repair-master-boot-record-mbr-windows

another fix is startup repair: change boot order so USB is first, hdd second
boot from installer
on screen after languages, choose repair this pc, not install.
choose troubleshoot
choose advanced
choose start up repair - this will scan PC and maybe fix this - will ask for logon info

see how they go for starters

 

[LukeFatwalker]

Your Boot Manager is compromised/damaged. Either way, you need to either repair the Boot Manager via Startup Repair or re-install the OS. Once you're back up and running I'd recommend backing up your data with a disk imager (i.e. Macrium Reflect) or a snapshot tool (i.e. RollBack Rx)