If your computer is over four years old forget about it. You will be DOOMED! DOOMED I TELL YOU!
I’m pretty sure you’re joking around. I’ve upgraded an eight year old laptop from win7 to 10 as a test. Went very smoothly without a single hiccup.
My only beef with MS latest OS is the heavy handed mandatory windows update scheme, specifically driver updates. I would prefer to choose whether to install drivers.
I upgraded a 10 year old Dell Inspiron 17 laptop with a core 2 duo and all sorts of proprietary hardware. It cam originally with Vista 32, I previously upgraded that one Windows 7 64 even though Dell refused to provide any support or drivers. That update was very difficult. I was beta testing Windows 7 on the Laptop and I needed to restore the vista install and then install Windows 7 and fix all of the issues. Same Laptop, I made sure all Windows 7 updates were installed, clicked go on Windows 10 and everything went off without a hitch.