Is it necessary to fresh win install after upgrading motherboard/CPU?

Do I have to do a fresh windows install after upgrading to a new motherboard and CPU?
And if it's really necessary, Can I get away with the "keep your existing file" option or do I need to clean format my drive before installing windows?

You don't need to re-install anything. Just make sure you meet the prerequisites to move the digital license from the old computer to the new computer:
https://support.microsoft.com/en-us/help/20530

That's so strange, I've done a few google search and asked couple of tech savy friends and almost every result is urging a fresh install after new hardware, Can I really get away with not doing a reinstall of windows?

NavyLCDR said:

You don't need to re-install anything. Just make sure you meet the prerequisites to move the digital license from the old computer to the new computer:
https://support.microsoft.com/en-us/help/20530

pezhmank said:

That's so strange, I've done a few google search and asked couple of tech savy friends and almost every result is urging a fresh install after new hardware, Can I really get away with not doing a reinstall of windows?

Yes. Microsoft even says so. Make sure the new computer is booting in the same mode the old computer did. If the old computer was legacy BIOS - the new computer needs to be set in legacy BIOS or CSM mode. If the old computer was booting in UEFI, the new computer needs to as well.

• https://support.microsoft.com/en-us/...ardware-change
• You reached the limit on the number of times you can reactivate Windows on your device.

What is that limit??