It's a spare machine and it's pitifully slow. $300 budget always looking for speed. Just recently took it from Windows 7 Pro
to Windows 10 Pro saw a dramatic drop in performance right away.
Changing from 7 to 10 shouldn't affect it dramatically. I have older core 2 duo pcs that didn't see a change with 10 and are speedy with just a ssd upgrade. You could have some other issue. What gpu does it have? Was it a clean install?