Have several different operating systems on the same computer.
Software that displays various important information from your computer on the wallpaper.
Utility for Windows that allows you to adjust the brightness of multiple monitors.

Application that allows you to install Windows 7 and 8 from a flash drive or external hard drive.
Utility that allows using the scroll button to scroll in any window, even if it's not in the foreground.
Software that allows you to update the firmware of NVIDIA video adapters.