Many people when they see Windows 10, they only see the new features and visual changes. For sure, they notice the new Start menu, Cortana, the Action Center, apps, including the new Settings app. However, many users fail to see that Windows 10 brings a lot of changes and improvements under-the-hood as well.

If you ever noticed, Microsoft made a lot of changes in Windows 10, and now the operating system uses even less space than its predecessor, Windows 8.x. In part, the changes were made to allow Windows 10 to run on devices with limited space, such as tablets and laptops with small size solid-state drives.

Also, the software maker was able to reduce the footprint of Windows 10 thanks to that the operating system no longer requires nor uses a recovery image. In fact, just by eliminating the recovery image, users get close to 4GB of storage back.

For recovery, the operating system now uses the files already in the system – more specifically the files found in C:\Windows\winsxs. However, there is one more component -- Windows 10 also includes a new compression mechanism known as Compact OS. Using the new tool takes the Windows 10 files and puts them into a hidden container where they are compressed freeing up more space (keep in mind that this method also compresses pre-loaded desktop applications).

This new method is what technically replaces WIMBoot from Windows 8.1 that offered similar advantages. You can still use this tool in Windows 8.1, but compact OS is easier to configure and deploy, and the best part is that you can even use it after you have installed Windows 10.

Now, there are a number of ways in which you can configure your compact OS (check this TechNet article). However, in this guide we're only going to focus on how you can use the tool to reduce the footprint of Windows 10, after you have installed the operating system.

Warning: While the compression tool works very well, you will be modifying your operating system installation. As such proceed at your own risk. Furthermore, it's highly recommended to create a full backup before making any changes to your PC.

  1. Compact OS is a command line tool, so you need to open the Start menu, do a search Command Prompt, right-click it, and select Run as administrator.
  2. Type COMPACT.EXE /CompactOS:always and hit Enter.

The tool will begin the process, which it will take anywhere from 10-20 minutes. Even better, you don't even need to restart your computer.

Here's a before and after image:

If you want to turn compression off, on step number 2, use the never switch, like this: COMPACT.EXE /CompactOS:never and hit Enter.

With the Windows 10 compression tool, you will be saving around a solid 2GB of storage space, but the amount of space will vary from system to system. While this might not seem like a lot of space for some users, if you are running the operating system on a device with limited storage, this could be a good amount of saved space.

In terms of performance, during my test I have not experienced any performance issues. Windows 10 and apps worked quite well as always.

Additional Resources

Do you need to more Windows 10 help? Use these guides and forums for more!

Windows 10 on Windows Central – All you need to know

Windows 10 help, tips, and tricks

Windows 10: Help and discussion forum at Windows Central