How to restore the normal Windows boot process before uninstalling Ubuntu

At this point I assume you already transferred all the files and documents you needed to save from your Linux operating system to a safe location outside your Linux partitions. If you installed Ubuntu alongside Windows, you need to fix the MBR before deleting the Linux partitions. To do so, the first step is to create a Windows 7 USB flash drive and boot on it.

Choose the settings you need.

Select the option to repair.

Start the command prompt.

 At the command prompt, type the following commands:

bootrec.exe /fixmbr

bootrec.exe /fixboot

Close the command prompt and click on restart. If you have problems booting Windows, have look here, you might find something you need.

Once you are in Windows, open the Disk Management tool and delete your Linux partitions.