I have one machine that runs 95 because it is an old system and it is just used by someone for playing solitaire and basic web browsing. Upgrading it would only make it peform worse. I think the computer was a new compaq system in 1997 or 1998.
I also have a laptop with Windows 98 on it. I do have it dual boot with redhat, but as for windows it would not serve me well to put xp on it. With 64 megs of ram and 300mhz cpu, XP would be of no use.
I still find some uses for these old machines, for sure!