I'm looking for a good, free C compiler for Windows so I can make some progress on K&R on my 13 hour flight tomorrow. Any suggestions?
Update: get an iso image for Linux and boot it during your flight? Its free its reliable and it is not going to take you hours of screwing around with.
There are plenty. Borland C++ Builder, GCC (on Windows, often used in Cygwin), DJGPP, Visual C++ Express, and LCC-Win32.
I've used GCC (through Linux and Cygwin). I used DJGPP years ago (it was/is a fork of GCC, don't know how close it has stayed) which worked very well. No experience with the rest, really.
Edit: and MingGW, which was already mentioned and may be your best bet if you don't want Cygwin.
Tiny C Compiler
Its about 200kb. Compiles 9x faster than GCC. No install, just unzip and go.
It doesn't optimize, but it should be fine for learning K&R
Visual Studio 2008 express edition, if you don't mind Microsoft products, is free, and has C++ support (so, therefore, C support).