In this day of age, it's very practical to have a Windows 7 installation on your USB key, for many netbooks and devices don't come with CD/DVD drives anymore.
Zip files are compressed archives containing documents, images, folders, basically any type of files on your computer. We create them to save space and make them more practical for sending via email or file sharing services.
A less known but very useful feature that works since Windows XP has been released. You can easily rename a bunch of files in a matter of seconds, let me show you how.