Reduce Windows 10 size With Built-in App Called CompactOS – The Steps

It's possible to Reduce Windows 10 size on a c: drive, but the mechanism has to be activated manually. It can safe few gigs of storage on your c: drive if you have space problems. The app is called CompactOS (command line utility) and contrary to WinBoot from W8.1, it can be configured (by simply running from command line) after Windows is installed. Previous release of Windows, which was Windows 8.1, was able to use WimBoot (It’s called Windows Image Boot) by using the restoration partition containing the recovery WIM image as target for booting the system. But it's utilisation was limited to SSDs (no hybrid or DD support).

How CompactOS works?

It's a new component Windows 10 which new compression mechanism known as Compact OS. Using the new tool , the Windows 10 files are putt into a hidden container where they are compressed. So by doing this you free more space on the root drive. I tried on my laptop with a 256Gb SSD and the tool has showed some 3-4 gigs of storage space savings after it's been run.

The big difference here is that unlike WIMBoot, CompactOS can be enabled and disabled as you wish.

The Commands line commands:

There are 3 commands that can be used to query, to activate or to deactivate the mechanism. The first one will simply query the system.

Compact.exe /CompactOS:query

This will query Windows to see if CompactOS is enabled or not. In my case the system did not activated the compression by default because the drive has plenty of space (over 60 gigs free) despite the fact that I run some VMs and using VMware Workstation.

Compact.exe /CompactOS:always

This will enable CompactOS

After few min of compression you'll get this screen…

Compact.exe /CompactOS:never

This will disable CompactOS

The tool is easy to use, but obviously there is a trade off. When accessing the compressed files, those has to be un-compressed on-the-fly so there might be a performance impact. In addition, the savings arent't that spectacular. As you can see, some 3 gigs of space was saved only.

So final worlds. Good to know it exists. If you need it, use it.

I know that I won't be using it as I privilege maximum speed and I do not need to recover space on my c: drive. The feature is there, that's the fact, but it does not mean that you have to use ALL feature of Windows 10, just because that there are there… -:) Enjoy.

Source: Technet