A Windows install is not nearly as modular as we all wish it were.
New motherboard + old drive and OS, there are 3 possible outcomes:
- It works just fine
- It fails completely
- It "works", but you're chasing issues for weeks/months.
Win 10 is much better than previous versions, but by no means 100% "just plug it in with the new hardware".
Increasingly, we are seeing #3. Initially "it works". Then...the issues appear.
For this level of change, I expect #2 or 3.
Plus, a fresh install lets you get rid of all the gunk you've built up over the years since that i7-930 was new.