If you are eliminating Ubuntu for 8, no comment, you may want to open your live ubuntu dvd you used for the install and use gparted to format the drive NTFS. Or another partitioner, there are several available. I'm surprised your win8 install doesn't do it for you. Or you could in Ubuntu shrink the partition it's on to make room for win8 bearing in mind win8 will erase the ubuntu launcher even though it's still there.