Windows 10: activation lost in a windows 10 reinstall

Hi,I have a problem with my laptop, an old but still good Dell Latitude.The machine has years ago Windows 8.1, from factory, and I upgraded to Windows 10 working fine more years.Now, I decided to reinstall it clearing everything. The setup and all worked perfect, BUT now the laptopis not activated. I tried to manually activated using the OEM key, recovered from hardware using "wmic" but I always get an error.I realize that since the original machine has Windows 8.1 the OEM key is for that and now doesn't work.I'm the owner of a valid license and I need it to convert it to Windows 10.Thanks in

:)

 

Upgrading cpu and mother without reinstalling windows 10

did it with a b250 motherboard upgrading to z270, did not need to reinstall anything, windows was still activated
did it with the z270 into z370 and lost windows activation, however did not have to reinstall any drivers, windows handled everything

i don't recommend doing it by going from amd > intel

 

How to reinstall Windows 10 if my computers used the free upgrade from 7 and 8?

Will windows 10 still accept the license keys from 7 and 8 now if I reinstall my computer?

Does Microsoft keep a list of users who upgraded to Win 10 using their 7 and 8 keys so that when users need to reinstall windows 10 the old keys would work?

Do I need to call in Microsoft to ask them to activate my Windows 10 when I give them my win 7 keys?

Both computers are laptops. The windows 7 machine had the serial printed on the back, and I needed to enter that when I upgraded to 10. The windows 8 machine had the serial built in inside its boot system so I didn't need to enter the key when I upgraded to 10, but I did manage to write down the keys using a fetcher program.

 

[Solved] Windows 10 keeps reinstalling KB3119142

I noticed quite some time ago that KB3119142 (Update for Microsoft Visual C++ 2012 Update 4 Redistributable Package) kept reinstalling itself for some reason. At least once daily. Sometimes up to several times a day. I just ignored it. It didn't seem to be doing any harm. And I figured they'd eventually fix it. Well...days turned into weeks, weeks into months, with no end to the problem in sight. It dragged on unsolved for at least the last few months. Literally reinstalling itself hundreds of(at least a hundred, felt like more) times in that period of time.

So I finally googled it a couple days ago. And just got around to fixing it today. Which appears to have worked. And it couldn't have been easier to do. I feel so stupid to have let it intimidate me for so long.*Oops!

Below are links to the thread that I got the fix idea from, and the official MS support info page for KB3119142(from which I quoted the above).
http://www.tenforums.com/windows-up...-windows-10-keeps-reinstalling-kb3119142.html
https://support.microsoft.com/en-us/kb/3119142