(Assuming you mean other than Kiss-C) I use linux, so I may not be of much help.
I have heard that Notepad++ serves as a nice light-weight IDE.
Geany and Gedit are available in Windows flavors. If you decide to use gedit, I would suggest the gmate plug-in set (as seen on on github), although it may require some use of cygwin and manual setup to get working on windows.
SciTE is very nice, small, and cross platform, but requires massive amounts of work to configure to your liking. (although it is the most customizable text editor out there)
The E-TextEditor looks nice (I love TextMate on the Mac), and is relatively inexpensive as far as IDEs go. (although I understand you want free)
A lot of people like Eclipse and NetBeans, but I find them kind of bloated due to their dependence on Java.
(Assuming you mean other than Kiss-C) I use linux, so I may not be of much help.
Asking on these forums for a generic question like this might not be the best place to start. I would suggest StackOverflow. They have a lot of questions and answers for questions like this. See: http://stackoverflow.com/questions/71786/windows-ide-editor-for-a-beginner
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I find gEdit bloated due to it's dependence on C. I would recommend emacs. :P
But in all seriousness, programmers notepad is awesome on windows.
Thanks,
Braden McDorman
"When you do things right, people won't know you've done anything at all."
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