Windows 10 can't repair or be restored

[hazencruz]

My wife's windows 10 PC randomly started acting strange after we finally attached one of her old HDD's to it for more storage.
After 2 days, it would randomly freeze when playing a video game, and need to be completely restarted.
When we restarted it tonight, it suddenly said it needed to "repair windows."
It failed to repair windows, and is now useless.
I've tried using a windows 10 ISO on a cd I made for my own computer (with the windows media creation tool) to restore a restore point or further diagnose or repair the PC, but I've had no luck.
I thought maybe it needed to be on a USB drive, so I tried to make a USB recovery drive, and ended up somehow making 2 of my old usb's completely useless now (windows recognizes they are there, but i can't format them, or open them.)
I can live without my thumb drives, but I just want my wife's computer to work again so she can enjoy her days off browsing the web and playing video games.
I've disconnected the SATA cable to the HDD we added, but windows 10 still isn't booting on her computer. It always tries to repair itself, and always says that repairing and restoring itself just doesn't work.
I thought I knew computers, but holy hell do I need some help.

 

[Lutfij]

Usual path to get system back up to functionality is to reinstall the OS from a newly created Windows 10 bootable installer via Windows Media Creation Tools. I would also like you to double check on the PSU since it's possible that the lack of power to your HDD might be what lead you here to begin with. Often times people think adding XYZ hardware to a system is easy-peasy but when layers are removed it's found out that the system had a bad PUS or a failing data cable and/or a grounding issue to lead to dead components.

 

[hazencruz]

Usual path to get system back up to functionality is to reinstall the OS from a newly created Windows 10 bootable installer via Windows Media Creation Tools. I would also like you to double check on the PSU since it's possible that the lack of power to your HDD might be what lead you here to begin with. Often times people think adding XYZ hardware to a system is easy-peasy but when layers are removed it's found out that the system had a bad PUS or a failing data cable and/or a grounding issue to lead to dead components.

The PSU is a 550 watt. I don't think it should be an issue to add a single HDD, but it could be a cable or something. Either way I've removed the drive, and the issue persists.

I misspoke before when I said the CD was a recovery drive, it is, in fact, a CD that I burned an ISO to with the windows Media Creation tool I downloaded here: https://www.microsoft.com/en-us/software-download/windows10