Advice with environment

I volunteered to help on a cross-platform thing called RockBox. RockBox is an open source firmware replacement for what comes with your iPod type digital audio player. It's ported for quite a few models and I'm helping out (just for fun and self-edification) with the Cowon iAudio 7, the player I happen to use.

Why? I want to learn C and the firmware on Cowon's iAudio 7 sucks, so I have a twin opportunity.

For reasons related to the task at hand, I must educate myself in C. Not C++, not C#, just C. This is my second language, my first being FORTRAN about 20 years ago. Point being, I'm functionally illiterate as a coder.

Re cross-platform environments & compilation, I am forced to use one of the following three. Given the choice between these compilers:
1. cygwin,
2. coLinux, or
3. VMWare
which of the above is least likely to get me into difficulty and easiest to conceptualize, compile and link plain ol' vanilla C language?

To make it simple, which compiler/linker would you recommend for me to use simply to learn how to program in C?

Since you are on Windows, start with Microsoft Visual C++. Learn with that compiler. Once you are sufficiently comfortable with C in that environment, you can consider the RockBox development environment.