Atmel Studio 6 is the IDE for developing and debugging Atmel ARM and Atmel AVR microcontroller applications.
Atmel Studio 6 System Requirements
Supported Operating Systems
Windows XP (x86) with Service Pack 3 – all editions except Starter Edition Windows Vista (x86 & x64) with Service Pack 1 – all editions except Starter Edition Windows 7 (x86 and x64) Windows Server 2003 (x86 & x64) with Service Pack 2 Windows Server 2003 R2 (x86 and x64) Windows Server 2008 (x86 and x64) with Service Pack 2 Windows Server 2008 R2 (x64)
AVR Studio 6 Supported Architectures:
32-Bit (x86) 64-Bit (x64)
AVR Studio 6 Hardware Requirements:
Computer that has a 1.6GHz or faster processor RAM 1 GB RAM for x86 2 GB RAM for x64 An additional 512 MB RAM if running in a Virtual Machine 4GB of available hard disk space A minimum display resolution of 1024 x 768 or higher is recommended.
Download Atmel Avr Studio 6 Free from following link
You may also need WinAvr