Boot the Ubuntu Live USB. Choose try Ubuntu without installing. When desktop loads open terminal and run without quotation marks "sudo apt-get install lilo"
Ignore warning and continue. Once installed run in terminal "sudo lilo -M /dev/sda mbr"
Once that command completes reboot without the Live USB and you should boot right to windows. You can then use Disk Management in Computer Administration in Control panel to either delete Linux partition(s) and create new NTFS partitions or delete Linux partitions(s) and have your C: extend to the unallocated space.
If not comfortable with terminal copy/paste commands I listed without quotation marks into terminal. You have GRUB2 on MBR. If you delete Ubuntu GRUB2 will still be there and you will get a grub rescue error because GRUB will be looking to the linux partition you deleted. You don't have recovery CD/DVD or a optical drive so lilo will put a generic windows bootloader on MBR for you.