How do I find the largest files and folders on a drive?

WinDirStat is great for finding large files on your drive, it's also easy to find if you have many files of a specific file type that takes a lot of space.

Check out Treesize. It's an awesome app that shows you the sizes of all the files/folders on your machine.

WinDirStat - displays a graphical view and list of files and directories, by size. There's a portable version at PortableApps.com if you don't want to install it.