Windows not working after upgrade?

[Sir Lags A Lot]

So I just upgraded from an i7 6700 to an i7 9700k. I also upgraded to an z390 board. Install went fine to no big surprise windows wont boot. Also, I use a Wd 1tb m.2 data ssd for boot. But no big surprise to me that windows had stroke. At first it gave me the code 0xc000000f. But I also had plugged in my 2.5 data hdd. So I unplugged it and the m.2 was alone. I plugged in a flash drive with windows install files to use startup repair. Said it could find any problems. I then went to the recover section but that said no windows installation was found. I shut the pc down and unplugged the flash. I turned it on again and it went straight to the bios. Repeat and went to the bios again. Plugged the flash back in and went to startup repair. Opened the command prompt and tried to repair the bcd files. But when I got to the y or n or a part I put y and it said nothing could be found on the drive. I fear that somehow my windows files got corrupted or even wiped with the rest of my files. I would use another windows install on a separate drive but I dont have one. That's pretty much it. If you have questions, ask away.

[Sir Lags A Lot]

Ok, so uh, it fixed it self after I plugged the hdd back in. I'm confused but happy. Now I just need to dial my 9700k to where it wont overload my noctua nh l9i

[DarkEnergy]

Couple things. Generally swapping a cpu and motherboard doesn't work nicely with previous windows installations. Your current windows installation may not be as reliable. Also, the Windows 10 activation should be tied to the motherboard. After swapping the motherboard I'd assume your windows is no longer activated, check and verify it's still activated.

[Sir Lags A Lot]

Yeah, its activated. No watermark thing. This windows key is voided though. It had originally came off of an hp sff. The modo broke on it so I moved my i7 off of that on an msi board.