Freeware: Remap

uControl 1.4.4 Remap many keys on your keyboard. uControl gives you the ability to take those useless keys, that you're certain would have been better fashioned as something else, and turn them into something useful.

DoubleCommand 1.5.2 Remap your keyboard keys. DoubleCommand is a kernel extension that lets you Remap keys on the keyboard.

X-Mouse Button Control 2.0X-Mouse Button Control is Windows software to Remap your mouse buttons and expand the capabilities of your pointing device, automatically conforming the mouse to your current usage needs through individual application or window class profiles!

MapKeyboard 1.2MapKeyboard is a free program to Remap the keys on your keyboard. Using MapKeyboard, you can alter any key on your keyboard to function as a different one or altogether disable it as well.

AutoHotkey 1.0.44.07\Automate almost anything by sending keystrokes and mouse clicks (macros). Create hotkeys for keyboard, mouse, and joystick. Expand abbreviations as you type them. Remap keys. Create custom data entry forms, user interfaces, and menu bars.

KeyboardRemap 1.0.1KeyboardRemap remaps your keyboard to the now-discontinued IBM split keyboard, which may make a gigantic difference in your ability to type without pain (along with better posture, exercise, etc.