To uninstall Ubuntu / Linux from a windows dual boot is very simple using EasyBCD program.
To Uninstall Ubuntu:
1. You’ll need to download and install EasyBCD.
2. Once installed run the program and click on BCD deployment from the Left menu.
3. Make sure that the radio button for the appropriate operating system is check.
4. Then click on Write MBR. when finished close the program and re-claim your partitions.