AutoHotkey is a free, open-source utility for Windows.

http://www.autohotkey.com/

Introduction

AutoHotkey is a free, open-source utility for Windows. With it, you can:
Automate almost anything by sending keystrokes and mouse clicks. You can write a mouse or keyboard macro by hand or use the macro recorder.
Create hotkeys for keyboard, joystick, and mouse. Virtually any key, button, or combination can become a hotkey.
Expand abbreviations as you type them. For example, typing "btw" can automatically produce "by the way".
Create custom data-entry forms, user interfaces, and menu bars. See GUI for details.
Remap keys and buttons on your keyboard, joystick, and mouse.
Respond to signals from hand-held remote controls via the WinLIRC client script.
Run existing AutoIt v2 scripts and enhance them with new capabilities.
Convert any script into an EXE file that can be run on computers that don't have AutoHotkey installed.

Getting started might be easier than you think. Check out the quick-start tutorial.
More About Hotkeys

AutoHotkey unleashes the full potential of your keyboard, joystick, and mouse. For example, in addition to the typical Control, Alt, and Shift modifiers, you can use the Windows key and the Capslock key as modifiers. In fact, you can make any key or mouse button act as a modifier. For these and other capabilities, see Advanced Hotkeys.
What Others Say

David A. Karp of PC Magazine: ...save time, keystrokes, and mouseclicks by making your own customized shortcuts ...lift the burden of repetitive tasks—like typing email replies—by doing them for you... [read the full article: Program Your Own Keyboard Shortcuts]

Wolfgang Reszel of c't Magazine: AutoHotkey sends several tools into retirement. It unites hotkey and text macros and offers a scripting-language, which is more powerful than every batch-file and easier to learn than the Windows-Scripting-Host. Beginners are able to start fast because of the scripting-language, similar to BASIC, contains a macro-recorder and syntax-checker. [read the full article: Simple automation of Windows and programs]

Dmitri Popov at NewsForge: Autohotkey features a combination that makes it a tool of choice for automating Windows: It's both powerful and easy to use. Whether you're a seasoned Windows administrator or an ordinary user, Autohotkey can make your computing life easier. [read the full article: Automating Windows with Autohotkey]

Adam Pash of Lifehacker: With AutoHotKey, I’m confident that I’ve trimmed the time I spend replying to emails down to a third of what it would be without. [read the full article: Knock down repetitive email with AutoHotKey]
Other Features
Change the volume, mute, and other settings of any soundcard.
Make any window transparent, always-on-top, or alter its shape.
Use a joystick or keyboard as a mouse.
Monitor your system. For example, close unwanted windows the moment they appear.
Retrieve and change the clipboard's contents, including file names copied from an Explorer window.
Disable or override Windows' own shortcut keys such as Win+E and Win+R.
Alleviate RSI with substitutes for Alt-Tab (using keys, mouse wheel, or buttons).
Customize the tray icon menu with your own icon, tooltip, menu items, and submenus.
Display dialog boxes, tooltips, balloon tips, and popup menus to interact with the user.
Perform scripted actions in response to system shutdown or logoff.
Detect how long the user has been idle. For example, run CPU intensive tasks only when the user is away.
Automate game actions by detecting images and pixel colors (this is intended for legitimate uses such as the alleviation of RSI).
Read, write, and parse text files more easily than in other languages.
Perform operation(s) upon a set of files that match a wildcard pattern.
Work with the registry and INI files.



Software License: GNU General Public License