GParted is a free disk partitioning tool that runs outside of the operating system. This means that you don't need to install an operating system to use it, and you never have to reboot to apply changes.

You can delete, format, resize, copy, hide any partition recognized by GParted, among other things.

There's little not to like about the GParted disk management tool:

GParted needs to be properly extracted to a disk or flash drive before you can use it. Go to the download page to download the ISO file. The download is the first link under the Stable Releases section.