Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Go to the Fedora Project Wiki and search for "uninstall Fedora."
You won't find anything.
Try "remove Fedora."
Go to Ubuntu's official documentation site and search for "uninstall Ubuntu."
You won't find anything in the "official" documentation but in the "community" section you find two entries that state "Wubi allows you to install and uninstall Ubuntu...."
In an installed Ubuntu distribution, clicking on Help and searching for uninstalling or removing Ubuntu finds nothing. A link “repeat the search online at the Ubuntu help pages” brings up a 404 – page not found.
If you look hard enough on the real community support pages you'll find a post from July 2007 titled "HowTo: Remove Ubuntu (& Restore Windows)" .