> I was pleasantly surprised when upgrade to Windows 10 actually worked on an old notebook I had (HP Compaq NC6400 -- it has a "designed for Windows XP, Windows Vista capable" sticker).

Just remembered that I now have an extra laptop, returned from our daughter. She went pro and bought a Mac, so this (4 year old) laptop was assigned the role of a back burner. It came back to me because it was made unusable after accepting the W10. I guess I'll boot some Linux from a flash drive, just to see if there are any data to salvage, and then decide what to install on it.