I got about 300KB free on my C drive sometimes. Yes. KB.
Time to scrounge something better - a 286-based machine perhaps.
I'm sure that you can find a better machine for free. Put a Wanted ad on Craigslist or Kijiji - "Don't dump your old computer in the landfill. Looking for donation of working 3-5 year old computer. Grateful for any offers." or "Times are tough. Looking for donation of working 3-5 year old computer. Grateful for any offers."
An ad like that ought to get you something WAAAAY better than what you have now. Just make sure it has Windows installed on it and has the Microsoft license sticker on the bottom.
Well if you really wanna know: 6 computers from 1982-1999 Atari 800, Commodore 128, Amstrad PC640, 386SX 20 MHz 2 MB, Pentium 1 166 MHz 32 MB and the one I use with the 'net Pentium 2 400 MHz 128 MB. Skipped the 286's, never had one -- 01/01/01