I would like to uninstall Ubuntu and bring my laptop back to DOS. I don’t have Windows on it. All the examples I have seen use Windows to uninstall. How do I do this?
If you want to use a live Ubuntu disk/usb, you could
"clear" the Ubuntu partitions. You would run gparted, choose your hard drive and format to "cleared" any partitions you want to effectively erase. I believe it is equivalent to running wipefs on the partition, though it does not really erase or overwrite the data.
[Excerpt from man page]
wipefs - wipe a filesystem signature from a device
DESCRIPTION
wipefs can erase filesystem or raid signatures (magic strings) from the specified
device to make the filesystem invisible for libblkid. wipefs does not erase the
filesystem itself nor any other data from the device.
Or you could just create a new Partition Table (in GParted, under the Device menu), that would erase (hide) all the partitions on the drive.
Then you would need a DOS install disk to install just DOS, though I don't think they're easy to find, according to Wikipedia the final MS-DOS release was in 2000. All the DOS install disks I've seen have been actual floppy disks, not many laptops have a floppy disk drive. You might want to try a web search for "reinstall windows", I found this site that sounds promising http://www.windowsreinstall.com/
OR just installing Windows (or DOS) will often overwrite any Ubuntu stuff, Windows is traditionally excellent at ignoring anything on your hard drive and just installing itself over top (whether you want to erase the other things or not). So first I'd try not removing Ubuntu, and just install something else.
