Heck, Windows 7 won't run on a Pentium-II (Win7 requires 1GHz CPU, Pentium-II only goes to 450MHz), much less a 486 or 386.
That's a 1997, 266 MHz Pentium II running Windows 7 Ultimate. Yes, it probably is quite slow - but it will run - and run with 96 MB of RAM at that.