How to Uninstall Ubuntu from Windows Dual Boot Safely

Last updated April 20, 2020 By Abhishek Prakash 187 Comments

Brief: This beginner’s guide shows you how to safely remove Ubuntu or any other Linux distribution from Windows dual boot.

Trust me, installing Ubuntu in dual boot with Windows is not that difficult a task. Similarly, removing Ubuntu from dual boot is also not that complicated.

In both cases, you need to take a bit of precautions with disk partitions. Having a Windows recovery and proper backups always helps.

In this tutorial, I am going to show you the steps for uninstalling Ubuntu from Windows dual boot. The steps should be equally valid for any other Linux distribution be it Linux Mint, Debian, Fedora, Arch etc.

Uninstall Ubuntu safely from Windows dual boot mode

The process is composed of two parts:

• Change the boot order in UEFI settings and give priority to Windows Boot Manager. You may also delete Grub entry from UEFI setting, if your system gives you this option. If that doesn’t work then you’ll have to repair boot with a bootable Windows disk.
• Deleting the Ubuntu partition from Windows.

As the last resort, you need to have a bootable Windows disk or recovery disk so that you can use it to repair the boot after removing Ubuntu (if needed).

Part 1: Run a sanity check and make Windows as default boot manager

I want you to have as few troubles as possible. And hence I recommend change the boot setting and make Windows boot manager as the default option to boot.

Let me explain a bit here. When you install Ubuntu or some other Linux, it adds Grub bootloader to your boot settings and makes it the default.

So, now your system has two boot loaders or boot manager (whatever you want to call it). Grub gives you option to boot into Ubuntu or Windows.

Windows boot manager lets you boot into Windows directly. And this is what you are going to use here.

Step 1: Access UEFI boot settings

Before you go on and delete the Linux partition, it will be a wise move to check if you can make Windows boot manager as the default boot option. This way, when you remove Linux, your boot process won’t be disturbed.

Access the UEFI settings from Windows. Search for UEFI and go to Change advanced startup options:

Click on Restart now:

On the blue screen next, select Troubleshoot:

Select Advanced Options next:

On the next screen, select UEFI Firmware Settings:

Hit restart button on the next screen:

Step 2: Move Windows Boot Manager up the boot order

Now your system will boot into UEFI settings. Now, the next screen will look different for different systems and manufacturers. You have to look for boot tab here.

On my Acer predator, it looks like the image below. Here, use arrow keys to select Windows Boot Manager and press F5 to move it up the order. Press F10 to save and exit.

Now, your system should boot straight into Windows. To verify, restart your system a couple of times and see if the system boots into Windows without showing the grub screen of Linux.

If that happens, you are good to go with the next step which is to delete the Linux partition and reclaim your disk space.

Part 2: Deleting Linux partition on Windows

Let’s see how to delete the Linux partition and extend your Windows disk with available freespace afterwards.

Step 1: Go to disk management

Log into Windows. Press Windows+R and type diskmgmt.msc into the dialog box. This will open the Windows disk management tool.

Step 2: Identify Linux partition

Since you installed Linux, it’ll be easy for you to recognize the Linux partition by its size.

Another hint for identifying the Linux partition is to look for those that don’t have a file system and drive number. Windows partitions are labeled with a drive number, such as C, D, E, etc., and usually use the NTFS or FAT file system.

As you can see, I have three Linux partitions here as I created root, swap and home separately when I installed Ubuntu.

Step 3: Delete Linux partition

Select the Linux partition(s), right click on them and opt for the Delete Volume option.

It will throw you a warning – just select Yes here.

Step 4: Extend Windows partition

The deleted partition(s) will now be available as a chunk of free space. You can either extend the existing volume or create a new Windows partition from it.

I would suggest that you create a new drive (or volume or partition, whatever you want to call it) as this will be easier if you decide to dual boot Linux with Windows again.

After deleting the Linux partition, of your system boots into a broken Grub screen which shows a message like grub rescue error, you need to use Windows recovery disk and fix the Windows bootloader.

Step 1:

Put in the Windows installation disk and restart your computer. Press F10 or F12 at boot time to go into BIOS/UEFI and choose to boot from removable disk.

Step 2:

Choose to repair your computer:

Step 3:

Go for the Troubleshoot option here:

Step 4:

On the troubleshooting page, choose Advanced options:

Step 5:

Look for the command prompt option in here:

Step 6:

In the command line, type the following command to fix the Windows boot loader:

Normally, it works instantly. You don’t even have to wait for it.

Step 7:

Once it’s done, restart your computer and this time boot normally from the hard disk. You should be able to boot into Windows. If you still see a Grub rescue error, try the steps below.

Step 8: If the trick in step 6 didn’t work

If the command in step 6 didn’t work, try Automatic repair from the advanced troubleshooting options.

It will take some time to find the issue and then repair it.

Now if you reboot, you should go into Windows normally without seeing any Grub rescue error thingy.

I hope this guide helped you safely remove Ubuntu from Windows dual boot. Feel free to ask any questions or make a suggestion.

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How to Uninstall Ubuntu From Your Computer

Make room for a new OS

Like with ordinary software, users occasionally migrate between operating systems as their needs dictate. Unlike with ordinary software, though, removing an OS is not as simple as uninstalling it from a menu, but requires wiping part or all of the hard drive to make room for a new OS.

If, as in this case, your computer runs only Ubuntu and you want to make room for something else, you have to erase your hard drive. Before proceeding, it should be noted that these instructions are not applicable if you have a dual-boot setup with Ubuntu and something else, as they will end up erasing all your installed OSes.

There are two main methods for doing this, the quick way and the secure way. The quick way is to just delete the partition headers that tell your computer how to read the data, making it as good as deleted as far as your computer can tell. This, however, leaves all your data just as it is, meaning that your data is forensically recoverable by certain programs. The secure way, on the other hand, is to overwrite the hard drive with a hard drive-sized string of random numbers. Although this takes several hours, and can’t really be interrupted (i.e. you should do it in one go), it writes over your data with indecipherable nonsense.

Both methods involve live-booting, as you can’t fully and properly delete an OS while that OS is running.

Determine Your Drive’s Size

Before booting into your live system, you will have to figure out the size of your computer’s onboard hard drive. This is to ensure that you overwrite the correct hard drive, as the system also recognizes the USB flash drive you live-boot from as a hard drive.

Start by removing any other USB devices from your computer. From here, boot into your current Ubuntu installation, open up the “Terminal” application, and run the following command.

This command runs a program which lists all detected (i.e. plugged-in) hard drives and then filters the output down to just the first line of information for each drive. Enter your user password, and after the terminal returns the filtered list, look for a line that starts (after “Disk”) with “/dev” but does not contain the word “loop”. After the first colon of this line, you should see the size listed. Write that number down, power off your machine and proceed to the actual overwriting.

Live-Boot With Ubuntu On A USB Drive

Since you are trying to remove Ubuntu, you probably still have the USB drive that you installed it from. Use this for live-booting over your Ubuntu installation to be deleted, so that your computer’s onboard hard drive will not be accessed at all while performing the wipe. If you don’t have your Ubuntu USB anymore, you can make one yourself.

Fast Deletion With the GParted Application

If you find running terminal commands intimidating and just want to quickly trash your hard drive’s data with a few taps, you can use a graphical disk management utility that comes preinstalled on Ubuntu called GParted.

Once you are booted into your live session of Ubuntu, find GParted in your application menu and open it. From here, do the following to delete your hard drive data.

1. Select the line with the Size matching the hard drive size you recorded from the steps in the last section.
2. Hit the icon with the red slash-through circle in the upper-left of the window.
3. Select the green check mark icon to the right of the now-grayed out delete icon (above).

This will permanently delete your operating system and all the data stored on it, so be very sure before confirming.

Once you are done with this, simply close GParted and shut down the live system and your onboard hard drive will be blank and ready for a new OS.

Fast Deletion With A Header Overwrite

After booting into a live Ubuntu session, open up the “Terminal” application and run this command to identify all disk devices.

There should only two results that don’t contain “loop”: one representing the USB the live session is running from, and the other representing your hard drive. Make note of the name under the “NAME” column which corresponds to the size your wrote down from the above verification process.

Now, run the following in your terminal where «hd_name» is the name you noted from the previous step

Your partition table headers are now gone, which means that your computer will, for all intents and purposes, think your hard drive is empty.

Thorough Deletion With A Full Disk Overwrite

The steps for this are initially the same as those for wiping the disk headers: start by live-booting your USB, opening up a terminal and determining the hard drive’s device name using the “lsblk” command. Again, the name (under “NAME”) in the row with a size matching your hard drive’s is the name of the drive to be wiped.

From here, run the following command, with “hd_name” replaced with the name you noted when you ran the «lsblk» command.

The “dd” command reads and writes raw bytes. While there is a lot going on in this command, the gist of all the options is that “dd” is reading data from your system’s random number generator and writing it in 4096-bit chunks directly to the hard drive, with no shortcuts taken for generating those random numbers.

Now you wait. A lot. When it’s done, though, you will have a drive filled with random, useless data, such that your previous data will not be easily recovered.