First of all download WinAVR. You can download newest stabile version. For all recent versions installation is mostly the same. Installing and Configuring WinAVR - Touches on everything, although 2 years out of date.
WINAVR is windows OS tool set for AVR microcontroller based projects. This package contains an AVR-GCC C/C++ compiler. Official site of WINAVR: http://winavr.sourceforge.net/index.html . In this site you can download everything needed to start your firrs AVR project. For this article am will using WinAVR20060421 stable distribution as it is tested and working version.
Probably many developers AVR microcontroller software had a question what compiler to choose for their designs. There are so many choices now in the real world. You can use commercial tool-sets like IAR, CodeVision, ImageCraft. These compilers are shipped with convenient user interfaces, code generators. But...you have to purchase a license to use full their potential. So if you decided to make low budget project, the best choice would be to use open source compiler GCC which has a big potential and it has strong position in society. This is the most successful open source compiler in the world, because it has support in all over the world, it is cheap, it doesn't depend on platform used. For AVR microcontroller platform compiler is called AVR-GCC.
ATMEL corporation is well known in the world wide of electronic component markets. ATMEL is one of leaders in producing modern electronic components like low energy, non-volatile, high speed memories, general purpose microcontrollers and microcontrollers with programmable logic.
This site will go through 8 bit general purpose RISC (Reduced Instruction Set Computers) microcontrollers so called AVR. Serial producing of AVR microcontrollers begun in 1996.
