Screenshot Taker on Windows 7 (or any platform, if possible) using C/C++

I wan开发者_StackOverflowt to code a program in C++ that takes screenshots and saves them. Can you suggest any sources to refer to?

I've seen several applications of this nature. Don't forget to include your platform.

http://www.rohitab.com/discuss/topic/22809-screenshot-c/
Screenshots in X11

Several things pop up instantly from Google =]