Just started today. Was able to let it automatic repair and boot up. Was on for like 10 hours, shut down and tried to boot up some hours later. Now its completely stuck on automatic repair. Have unplugged all additional hdd's and then all unnesscarry USB's. Still doing this. Also removed my ethernet card. Still the same.
I cannot lose my data. I have several SSD's and HDD's with important files across several of them.
Not saying that is for sure the culprit, but could be worth a try if you're not getting anywhere with other solutions. Especially if the system keeps hanging at the BIOS screen before even attempting to boot to USB or Windows.
It's possible your original build just started out with an older battery so with some luck a replacement could be an easy and cheap fix :)
Could that be the culprit? Why was it fine for almost a whole week?
Oddly that's how those issues tend to manifest themselves. You start having unreliable boot ups, sometimes it hangs at the BIOS because it lost the prior BIOS config, and somehow the next startup manages to keep going with defaults.
Unfortunately even if that is the issue and you fix it, the prior Windows installation may be pretty broken if it is unable to fix itself.. if you manage to get to the point that you consistently get past the BIOS, and Windows itself isn't repairing it, then maybe the next step is booting off a Windows 10 USB and try to do a repair from there.
Also maybe start thinking about how you'll back up your data in the case you need to start over with a fresh Windows install.. since it's Windows 10 maybe the universe is telling you it's time to move onto Windows 11 or migrate over to the world of Linux but that's your call to make.