If you have a single-boot system with only Ubuntu installed, you can install Windows directly and override Ubuntu completely. To remove Ubuntu from a Ubuntu/Windows dual boot system, you will first need to replace the GRUB bootloader with the Windows bootloader. Then, you would need to remove the Ubuntu partitions.
The first step can be done with a Windows Recovery DVD/Installation DVD or a Ubuntu Live DVD. If you have a newer Dell laptop (such as the Dell Inspiron), you would need to do so by changing the boot sequence in the UEFI settings, which will be discussed later.
Using Windows Recovery or Installation Media
If you don't have a Windows recovery or installation media, you can download official ISO files for Windows 10, Windows 8, or Windows 7 from the Microsoft Download Center and burn them on a DVD or a USB drive. Windows will only install as an evaluation copy for 30 days without a genuine product key.
Grab a Windows recovery or installation media and boot from it. You should see this or a similar screen on a recovery media.
You should see this on an installation media. Click "Repair your computer" and you should see a screen like the first image.
Open the Command Prompt, then type
bootrec /fixmbr into the Command Prompt.
Reboot and boot into Windows. Then follow the steps below to remove the Ubuntu partitions.
Using a Ubuntu Live DVD and Boot Repair
If you don't have a Windows recovery CD or you are constrained to download and burn the ISO files mentioned before, you can use Boot-repair. It is a tool that fixes most boot problems(Windows or Ubuntu). I suggest using a Windows CD if possible.
Boot from a Ubuntu Live DVD or USB
Type these lines in the terminal one line at a time.
sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install boot-repair
Search for Boot-Repair in the Dash and launch it.
To fix your computer with Boot-repair, simply click the "Recommended Repair" button. Then follow the steps below to remove the Ubuntu Partitions.
Changing the Boot Sequence in the UEFI settings of a Dell computer
Newer Dell laptops like the Dell Inspiron requires the bootloader order to be changed directly in the UEFI settings. This can be done with the following steps.
- Pressing F12 when the Dell logo appears.
- Go to
Boot Sequence. Under the Boot Sequence section, select
Ubuntu, then click
Delete Boot Option.
- Reboot your computer.
Deleting Ubuntu Partitions
After the previous steps, your computer should boot directly into Windows.
Go to Start, right click Computer, then select Manage. Then select Disk Management from the sidebar.
Right-click your Ubuntu partitions and select "Delete". Check before you delete!
Then, right-click the partition that is on the Left of the free space. Select "Extend Volume". Go through the Wizard and Finish it.
Note from Tanner: If you are using an extended partition, you might have to remove the big extended partition to make the space unallocated.