My parents have an old Compaq Presario SR1950NX that works perfectly fine, but hasn’t been used in at least 15 years. Obviously I can’t connect it to the internet with Windows XP, but before I recycle it I thought I’d see if anyone had any cool ideas for how I could use it. I’m sure I could find Linux distro that would work, but I don’t really need another desktop PC in the house.
Others have said NAS, and it might be a bit slow, but it would probably be a fun little project. If it has any PCI-Express slots open, you could maybe find a Gigabit network card somewhere and throw that in, since I’m sure that thing has a 100Mbit connection.
Having a 64-bit processor really opens up the number of distros you can install lol. As someone else had said, keep in mind the power usage of something that old.