There was a mention of concern about whether a "particular" MIDI device would be XP compatible. The MIDI signal normally goes into your soundcard, and its the soundcard that's plugged in - in your machine - that needs to be XP compatible. WinXP shouldn't care what the MIDI source is, if it produces "legal" MIDI output, since MIDI is "just a string of numbers," and the numbers are the same regardless of where, or what kind of device, they come from.

Also, as commented before, some of the newest soundcards are dropping the MIDI connector on the main faceplate in order to mount multiple (usually 5, but up to 7) "surround sound" speaker jacks. Nearly all "older," not necessarily very old, soundcards should have a MIDI jack on the slot plate attached to the card, or be wired to the "second" Joystick/Mouse jack, possibly needing an adapter. With some new soundcards, you may have to use another slot to mount a "piggyback" slot plate to get an external MIDI connector of any kind, since the only place provided for making a MIDI input is a connector on the card (i.e. inside the computer).

John