use gparted to reformat hard drive to NTFS
The best way I've found to do what you want to do is to use GParted (http://gparted.sourceforge.net) to delete the partitions, install a (or several) new partition(s), and then reformat your hard drive to NTFS. GParted is a Linux live disk of about 125 megs that works wholly in memory - you can prepare it easily by downloading GParted from sourceforge (or from www.distrowatch.com), from CNET, or from several other sources - and then burn it onto a CD when using Ubuntu You can also put it on a flashdrive via Ubuntu, or via Tuxboot. Then you boot the laptop with GParted running in memory, and use the top bar to do what you want with the hard drive. Given that you're giving up your Ubuntu OS, experiment until you find the size of the partition you want, and format that to NTFS. I use GParted routinely, and just recently used it to prepare partitions on my laptop for Windows 7 on one . and Ubuntu 10.10 on a second. Both work splendidly.