To Uninstall Ubuntu from a Windows 8 dual boot is very simple using EasyBCD 2.2 program.
Uninstall Ubuntu from a Windows 8 Dualboot:
1. You’ll need to download and install EasyBCD 2.2.
2. Once installed run the program and click on BCD deployment from the left menu.
3. Make sure under BCD Deployment that the radio button for windows Vista / 7 system is checked.
4. Then click on Write MBR. when finished Click on Edit Boot Menu.
5. To the right of Windows 8 Place a check mark to the left side of yes under Default.