Old windows 10 hard drive works with new build why?

[bork9312]

I have just upgraded my pc from fx-8350 gigabyte970 board to a Ryzen5 1600 and Rog Strix b350 board. I booted with my old hard drive went into my bios at first (didn't change anything and closed bios). It had the ASUS logo and a spinning wheel (looked like windows with spinning dots) underneath and said setting up hardware or something in that nature. After awhile it booted windows as if I haven't changed my components at all. I did have to relog into Windows One Drive but its still says my windows is active in the settings. I have a digital license linked to my Microsoft account prior to the upgrade but has not asked me to re-enter the activation key. Am I ok to keep using this version of windows or will there be problems in the future?

 

[Gam3r01]

Its highly rare for it to work like that, especially after a substantial change.
Personally, I would reinstall windows to avoid any future issues, or issues it may have that you just havent noticed yet (driver issues, improper hardware id, etc).
On the new install you just skip the key and/or log into your MS account to activate it.

 

[USAFRet]

I have just upgraded my pc from fx-8350 gigabyte970 board to a Ryzen5 1600 and Rog Strix b350 board. I booted with my old hard drive went into my bios at first (didn't change anything and closed bios). It had the ASUS logo and a spinning wheel (looked like windows with spinning dots) underneath and said setting up hardware or something in that nature. After awhile it booted windows as if I haven't changed my components at all. I did have to relog into Windows One Drive but its still says my windows is active in the settings. I have a digital license linked to my Microsoft account prior to the upgrade but has not asked me to re-enter the activation key. Am I ok to keep using this version of windows or will there be problems in the future?

Sometimes it works, sometimes it fails.

Basically, 3 possibilities:
1. It boots up just fine
2. It fails completely
3. It boots up, but you're chasing little issues for weeks

 

[jojesa]

I have just upgraded my pc from fx-8350 gigabyte970 board to a Ryzen5 1600 and Rog Strix b350 board. I booted with my old hard drive went into my bios at first (didn't change anything and closed bios). It had the ASUS logo and a spinning wheel (looked like windows with spinning dots) underneath and said setting up hardware or something in that nature. After awhile it booted windows as if I haven't changed my components at all. I did have to relog into Windows One Drive but its still says my windows is active in the settings. I have a digital license linked to my Microsoft account prior to the upgrade but has not asked me to re-enter the activation key. Am I ok to keep using this version of windows or will there be problems in the future?

I have done the same several times and you may not have any issues at all. But I have encountered freezes, hangs and BSOD in a couple of systems and I had to perform a clean installation.
To mitigate issues, I usually remove all drivers and apps related to the old hardware before removing the disk from the old system.
Depending on your license and when you use a Microsoft account, Windows 10 activate itself as soon as you connect to the internet.