In this guide, you will learn how to completely remove Ubuntu from a computer dual-booted with Windows 11. This process involves identifying the Linux partition, deleting it to reclaim space for Windows, and cleaning up the EFI boot partition to remove the GRUB bootloader.
Before deleting anything, it is best practice to verify the exact size of the Ubuntu partition while logged into Linux. This ensures you identify the correct volume later in Windows.
Boot into Ubuntu. Open the start menu and search for "Disks". Locate your main hard drive and identify the Ubuntu partition. It is usually formatted as ext4 and labeled "Linux Filesystem".
Note the size (e.g., 25 GB). Once you have confirmed this, restart the computer and boot into Windows 11.
Once you are in Windows, you need to remove the volume that contains the Linux installation and merge that space back into your main Windows drive.
Right-click on the Windows Start menu and select Disk Management.
Locate the partition that matches the size you noted earlier (e.g., 24-25 GB). Right-click this partition and select Delete Volume. Confirm the deletion by clicking "Yes". The space will now appear as "Unallocated".
To reclaim the space, right-click on your primary Windows partition (usually C:). Select Extend Volume. Click Next through the wizard to assign all available unallocated space to the Windows drive, then click Finish.
You can verify this by opening File Explorer; your C: drive should now show its full original capacity.
Even though the data partition is gone, the boot entries (GRUB) still exist in the EFI System Partition. We need to remove these to ensure the system boots directly into Windows.
Right-click the Start menu and select Terminal (Admin) or Command Prompt (Admin).
Run the diskpart tool and execute the following commands to locate your disk and system partition:
diskpart
list disk
select disk 0
list part
Look for the "System" partition, which is usually around 100 MB. Select it and assign it a drive letter (for example, K):
select partition 1
assign letter=K
Explorer usually blocks access to the EFI partition, but we can bypass this using Task Manager.
Go into the EFI folder. You will see a folder named ubuntu. Highlight this folder and delete it.
Close the browse window and return to your terminal. Remove the drive letter you assigned earlier:
remove letter=K
exit
Restart your computer. The GRUB bootloader should be gone, and Windows 11 will boot automatically.