How do I wipe my computer completely clean and remove ubuntu? [duplicate]

Solution 1:

formatting does not delete the data, you need to write data to the drive. Boot a live CD and either write zeros to the hard drive with dd or use a utility such as shread

dd if=/dev/zero of=/dev/sda iflag=nocache oflag=direct bs=4096

or use a utility such as scrub

scrub /dev/sda

http://linux.die.net/man/1/scrub

See Securely erase hard drive using the Disk Utility

https://wiki.archlinux.org/index.php/Securely_wipe_disk

You then format the hard drive and install your os of choice

Solution 2:

That would be reformatting the drive. You can probably do this automatically when installing windows. Otherwise, you can also use a utility program do do it ahead of time. You could boot an OS from a live DVD, to get a running OS without having your harddisk mounted, and then use a disk utility from that live DVD's OS to nuke the the disk. Better make sure you don't have any data.