In Windows, for as long back as I can remember, ALT-Space has been the keyboard combination to display the Window Menu. This menu is anchored to your application icon in the top-left of every window, and provides keyboard access to functions such as Move, Size, Minimize, Maximize and Close.
This feature is especially useful if you suspect a window has appeared off the right edge of your screen. If you change screen resolutions a lot then you'll find this can happen quite often. By selecting ALT-Space, M and then holding down the left cursor key you can move the window left and back on to the screen.
When the window is then visible, pressing the Enter key will give you mouse control back and the window in the new location, whilst pressing Esc will return the window to it's original location.
Why do I mention this? Because when you do a default installation of Launchy, this is the Hotkey combination mapped to display the application. This application is provided to give keyboard-centric users fast access to applications, and yet it replaces a fundamental feature present in all versions of Windows.
Luckily though, the developers have made it easy to change. After installation, display the Launchy interface by pressing ALT-Space, then right-click anywhere except the textbox and select Options from the context menu.
You can then modify the Hotkey to be the Windows-Space combination (as shown in the screenshot). On most keyboards (except for laptops), the Windows key is right next to the ALT key, so this option works really well. You can also ensure that Launchy always opens in the middle of your screen with the Always Center Launchy option.