NSIS (Nullsoft Scriptable Install System) - is a professional open source system to create Windows installers. It is designed to be as small and flexible as possible and is therefore very suitable for internet distribution. Being a user's first experience with your product, a stable and reliable installer is an important component of successful software. With NSIS you can create such installers that are capable of doing everything that is needed to setup your software.
Features
• Generates self-contained executable installers
• Page system: You can add standard wizard pages or custom pages
• Optional silent mode for automated installations
• A preprocessor with support for defined symbols, macros, conditional compilation, standard predefines
• A lovely coding experience with elements of PHP and assembly (includes user variables, a stack, real flow control, etc.)
• Registry key reading/setting/enumerating/deleting
• INI file reading/writing
• Generic text file reading/writing
• Powerful string and integer manipulation
• User selection of installation components, tree for component selection
• Multiple install configurations (usually Minimal, Typical, Full), and custom configuration
• Installer self-verification using a CRC32 checksum
• Small overhead over compressed data size (34 KB with default options)
• Ability to display a license agreement in text or RTF format
• Ability to detect destination directory from the registry
• Easy to use plug-in system (lots of plug-ins for creation of custom dialogs, internet connections, HTTP downloading, file patching, Win32 API calls, etc. are included)
• Installers can be as large as 2GB
• Window finding based on class name or title
• Callback functions for user actions
• Completely free for any use.
• And more..
Download: 
NSIS Nullsoft Scriptable Install System 3.11.rar - 4.6 MB