How To Shrink Windows 10 To Make Space For Linux

Introduction

This tutorial is part of a larger guide showing how to dual boot Windows 10 and Ubuntu Linux. 

Regardless as to whether you wish to dual boot with Ubuntu or any other version of Linux you will need to make space for it and if you only have one hard drive the only way to do that is to reduce the amount of space that Windows is using.

This procedure is very safe as long as you don't try and shrink any further than the shrink tool suggests.

It is definitely worth checking out this guide for backing up Windows 10 first if you haven't already seen it. It is better to be safe than sorry.

The tool used for shrinking Windows partitions is “Disk Management”.

To start "Disk Management", right click on the Windows start button in the bottom left corner of the screen and click on the “Disk Management” option.

A screen will appear listing all the disks available to you and the partitions on the disk that is selected within the window.

The hard drive is usually disk 0. It is usually easy to spot because it is larger than the other drives and already has a number of partitions on it. As you can see from the image above there are 4 partitions. The amount of partitions on your hard drive may differ.

For example the screenshot above shows the partitions on my computer which used to run Windows 8 (UEFI) and the screenshot below shows the partitions on my computer which used to run Windows 7 (BIOS).

What you are looking for is the NTFS partition which is both active and primary. In most cases it is drive C. It is also likely to be the largest partition on the drive.

NOTE: If your computer does not have an EFI partition and there are 4 partitions on the drive which say primary then you should read this guide before continuing as you cannot have more that 4 primary partitions on a non-EFI drive.

Right click on the partition which contains Windows (as described above, probably the C drive, NTFS file format, primary and active).

Click on the “shrink volume” option.

When the shrink dialogue box appears it will have the maximum amount of space available to shrink listed with an up and down arrow to increase or decrease the amount of space made available to Ubuntu.

Do not make the number if the “Enter the amount of space to shrink in MB” (box 3) larger than the “Size of available shrink space in MB” (box 2). This is the equivalent to ghostbusters crossing the streams.

You can make the amount of space available to Ubuntu smaller though. The minimum required by Ubuntu is 7 gigabytes which is 7000 megabytes. In reality you should be looking to give at least 20 gigabytes (20000 megabytes) to Ubuntu for a decent experience and if you have it I would go for 50 gigabytes (50000 megabytes).

Of course if you so wish you can leave the recommended amounts as they are.

When you have decided on an amount enter it into the box and click “Shrink”.

When the process has finished you should see that the C drive has become much smaller (or smaller by the amount you entered in the shrink dialogue box and that a new unallocated portion of disk space has appeared.

You now have space to fit at least one Linux distribution alongside Windows 10.