OS-Uninstaller is a small graphical tool to perform a clean and quick uninstall of any operating system (Windows, OS X, MacOS, Ubuntu, other Linux distributions...) from your computer.
Features
It supports removing only selected OS boot list entries in the GRUB.
Or completely remove the GRUB and replace it with the original MBR (master boot record) that was there before installing Ubuntu.
It also automatically reformats the partition of the OS that you just removed into NTFS (default) or ext4, depending on the OS that was there before.
Change the GRUB menu’s display timeout.
Backup the partition table and the boot sectors (just in case).
It also lets you manually change the MBR and its installed location of hard disk and the partition it’s linking for booting. But for most users, you don't have to tweak any of these.
Download Boot-Repair-Disk. Then create a live USB flash drive of it.
In order to make a Boot-Repair live USB, use UNetbootin. The flash drive you use should be 1GB or larger and formatted to FAT32. The formatting procedure will delete all of the files that are already on the flash drive.
In UNetbootin click the Diskimage radio button and then click the ... button.
Select the boot-repair-disk ISO file that you downloaded and click the Open button.
It is very important to verify that the device that you are installing the boot-repair-disk ISO to is indeed your flash drive, so that you don't overwrite any of your system or personal files which may make your operating system unbootable. In OS X you can find the device name of the USB flash drive using Disk Utility.
In the first screenshot the name of the USB drive is /dev/disk0s4
To boot the Boot Repair live USB on a Mac:
- Insert the USB drive into an available USB port.
- Reboot or turn on the Mac.
- Immediately after the startup chime, press the Option key (sometimes marked Alt).
- Select the USB drive from which to boot by using the left and right arrow and Enter keys.
Boot from the Boot Repair live USB. A window (Boot-Repair) will appear, close it. Then launch OS-Uninstaller from the bottom left menu.