How can I remove Ubuntu OS and then install Windows?

OK like the other 2 said ya bios>CD> that crap then to completely remove Ubuntu DELETE the old partion yes delete the old partion if you don't and you try to install it from partion1 you'll go through the whole process and then when you restart it no operating system, so once you do soo in one of the scenes you would see Partion[RAW] and then there you go.