Uninstall Ubuntu 14.04 on dual boot system with Windows 10

I wish to uninstall Ubuntu 14.04 from my dual boot machine. I had installed Ubuntu 14.04 with Windows 10. Currently I boot with GRUB and not windows bootloader. I have read on the internet that it is a safe choice to move to windows bootloader before uninstalling Ubuntu otherwise it will corrupt my windows files. Kindly suggest me a way to uninstall Ubuntu 14.04. There might be similar links available but they are about Windows 7. Windows 10 uses UEFI rather than BIOS (Windows 7) and instructions are outdated. Also detail out the steps required to change to the windows bootloader from GRUB.

In case you want to point me to some other questions/instructions please feel free. I just want to make sure that someone has tried or vet other/outdated answers.

Note - I will reinstall Ubuntu 14.04 once again but later; so if you have tips regarding making a fresh dual boot installation please mention them, and I don't want to use easyBCD for changing to bootloader

Notable links - How to remove Ubuntu and put Windows back on,
How to geek - deleting Ubuntu partition,
Changing to bootloader askUbuntu

--3 parts--
1. Changing to bootloader + taking other precautionary measures to minimize the risk of corrupting Windows
2. Uninstalling Ubuntu 14.04 (including reformatting the hard disk and getting back the memory space in Windows)
3. Fresh install with Windows Tips (Optional) :D

Answer

Windows boot files are placed in \EFI\Microsoft and Ubuntu boot files (GRUB) are placed in \EFI\ubuntu on EFI System Partition (ESP).

A simple change of UEFI boot order (stored in NVRAM) which would place Windows entry as first boot choice would be enough. Then, you can delete Ubuntu partition.

To achieve this:

In UEFI setup on your computer there should be a separate screen for setting boot where you can reorder which device or boot entry to boot first. Usually this list contains USB device, DVD device and boot entries from OS installed on disk.

If there is no way to reorder boot choices by using UEFI firmware setup, you could just delete "\EFI\ubuntu" folder on ESP.

To do this, open an admin command prompt:

1. Map ESP using diskpart.exe to drive Z: (alternatively you can use Dual-boot Repair tool which maps ESP to drive Z: on start )



2. Issue the following commands:

   
   

   z:
   

   
   

   This selects z: drive as current

   
   

   rd /s \EFI\ubuntu
   

   
   

   This deletes the folder

You can also use any bootable USB/DVD with Windows or Ubuntu to delete "EFI\ubuntu" directory from EFI System partition.

After a reboot, the UEFI boot entry for Ubuntu should not exist anymore.

Then, you can simply delete Ubuntu partition using Windows Disk Management or some third party disk tool.

Notes:

1. I would suggest if you have enough free disk space you just copy (recursively) "\EFI\ubuntu" folder to a safe place and then delete it from ESP. This way you still have Ubuntu installed but not in boot menu. Copying back \EFI\ubuntu would
   bring it back to boot menu.


2. There is a connection between EFI boot menu (stored in NVRAM - not to be confused with Windows or GRUB boot menu) and the folders (Microsoft, Ubuntu) on ESP. Usually (dependent on implementation) EFI firmware checks boot menu entries on computer startup and dynamically adds or deletes boot menu entries if corresponding files exist or do not exist on disk.