Old computers that can't run new versions of Windows at an acceptable level of performance can still be useful.
Try installing a free operating system like ReactOS, OpenBSD, NetBSD, FreeBSD, GhostBSD, or Debian GNU/Linux -- or pay a friendly local techie to do it for you.
It might not play your favorite games or run your favorite apps, but if you're willing to learn you can escape the upgrade treadmill, save money, and stick it to the man.