Is it http://bellard.org/tcc/ – ? Looks interesting: I think it’s great that you’re doing it this way. Really gives an appreciation for libraries and things when you use a straight compiler with no frills.
Also, if you want to stay minimalist yet stay native to Windows, consider http://www.mingw.org/ when you’re ready.
It’s a minimalist step ‘up’ in the C world without giving you too much ,if you’re going the “I’m going to make it as hard as possible on myself and still succeed” route. [which i do something: I love learning languages I don’t know].
[that being said, I haven’t used either of them. I can modify C and recompile it if I must, but from scratch? Nope]