Ok I have recently made some mistakes with installing some operating systems that I should have just kept on a live cd not ubuntu but another os and with my ocd when I saw my lot's of different partitions I just wanted to reset my computer so it boot's up and doesn't load any os and I have to put in my ubuntu live cd and install that and that would be my only os on this computer so I want to know how I can just wipe my entire hard drive so when it boot's I get to put my live cd in and start anew?