Windows 10: Compress or Uncompress Windows 10 with Compact OS

How to: Compress or Uncompress Windows 10 with Compact OS

How to Compress or Uncompress Windows 10 with Compact OS


Windows 10 includes tools to help you use less drive space. You can now compress the files for the entire operating system, including your preloaded desktop applications. Compact OS lets you run the operating system from compressed files (similar to WIMBoot in Windows 8.1 Update 1), and single-instancing helps you run your pre-loaded Windows desktop applications in compressed files. The new processes helps maintain a small footprint over time by using individual files, rather than combining them in a WIM file.

Windows 10 can efficiently compress system files. That gives back approximately 1.5GB of storage for 32-bit and 2.6GB of storage for 64-bit Windows.

Compact OS is supported on both UEFI-based and Legacy BIOS-based Windows 10 installations.

For more details about Compact OS in Windows 10, see:

• Compact OS, single-instancing, and image optimization | Microsoft Docs
• How Windows 10 achieves its compact footprint | Windows Experience Blog
• compact | Microsoft Docs

This tutorial will show you how to use Compact OS to manually compress or uncompress your Windows 10 system.

*note You must be signed in as an administrator to be able use Compact OS.




Here's How:

1. Open an elevated command prompt.

2. Do step 3 (query), step 4 (compress), or step 5 (uncompress) below for what you would like to do.


3. To Query Current System Compact State
A) Copy and paste the command below into the command prompt, press Enter to see if your Windows 10 is currently in the compact state (compressed), and go to step 4 (compress), step 5 (uncompress), or step 6 below.

*Arrow compact /compactos:query








4. To Compress Windows 10 OS Binaries (system files)
A) Copy and paste the command below into the command prompt, press Enter, and go to step 6 below.

*note It can take a while to finish compressing.

*Arrow compact /compactos:always





5. To Uncompress Windows 10 OS Binaries (system files)
A) Copy and paste the command below into the command prompt, press Enter, and go to step 6 below.

*note It can take a while to finish uncompressing.

*Arrow compact /compactos:never





6. When finished, you can close the elevated command prompt if you like.


That's it,
Shawn


Related Tutorials

• How to Add Compact OS Context Menu in Windows 10
• How to Compress or Uncompress Files and Folders in Windows 10

:)

 

How to free up disk space in Windows

In answer to uncleClav, there has been no noticeable difference in speed or operations of the OS. And yes you can reverse the compress operation.

See link. Compress or Uncompress Windows 10 with Compact OS

Hope this helps

 

Windows 10 Apps default location

I saved about 2GB by using the new Windows 10 Compact OS feature, which is only meant for flash storage and SSD's.

At an Administrator Command prompt:

compact /CompactOs:query <-- this will Query the system's Compact state.

compact /CompactOs:always <-- This will Compress all OS binaries and set the system state to Compact

/CompactOs Set or query the system's compression state. Supported options are:

query - Query the system's Compact state.

always - Compress all OS binaries and set the system state to Compact

which remains unless administrator changes it.

never - Uncompress all OS binaries and set the system state to non

Compact which remains unless administrator changes it.

 

Maybe, maybe not. When I upgraded my OS was compacted, when I clean installed on same hardware it wasn't. I did an in-place upgrade and it was again.... The exact conditions that the system uses to decide aren't documented that I can see - some combination of RAM/CPU/Free Space/Disk

You can always try it and turn it off again if it is slower. It may even be faster (slow disk, fast CPU for example) - it depends on your specific set-up..

 

Actually I had the same - I have a tablet which was running 8.1, and when I upgraded, CompactOS was on, but after a clean-install it wasn't.

In my case I'm assuming it was because the clean-install didn't have the right drivers (I had to add some manually), and my best guess was that the disk didn't look like a solid-state device and that tipped the balance so it decided not to compact.

 

It could be drivers - I had to add some also - I just assumed free space. Really I don't know though.

If your interested in saving more space I've also compacted these directories with compact /c /s /a /f /q /i /exe:xpress16k ... I've not seen any performance difference but it saves a lot of space, especially if you have Office...

Most other big directories I've tried seem to stop Windows booting or otherwise behave badly (programdata, appdata, system32\driverstore\filerepository for example) but these work OK.

Code: $envrogramFiles $envrogramFiles(x86) $env:homeDrive\MSOCache $env:homeDrive$env:homePath\Documents $env:windir\Assembly $env:windir\InfusedApps $env:windir\Installer $env:windir\Panther $env:windir\SoftwareDistribution $env:windir\System32\Catroot2 $env:windir\System32\LogFiles[/quote]

 

Yeah, that's pretty much just a generic message basically meaning that Windows determined that you didn't needed to compress.

It doesn't mean that it will hurt or improve performance.

 

Thank you for this post ! I decided to try out a super cheap laptop with only 32GB as a travel device. Bad idea. mostly because Windows 10 really needs a 64GB drive if you want to install some standard apps and still have enough room for performance. That said, this device came with the OS compacted. I decided to turn that off and see what the performance is like since task manager showed compression as a major resource sucked. Long story short, uncompressing only cost me 1GB is space. Before that Windows 10 was using 10GB of space. So the net gain on compression was only 10%, not at all worth it. Personally, I would keep the OS uncompressed.

 

Did you find any performance difference? In my testing I've found uncompressed to be the slowest even if you have SSD (not that it would always be the case). See this thread for example Any useful scenario for NTFS compression? - Page 2 - Windows 10 Forums

 

[/quote] Can someone post what the compact switches do that are listed in this post?

 

Hello Mansome,

Here you go. *Smile

 

I encountered problems with PerfectDisk 14 boot-time defragmentation with the compact option on.
The error was a blue-screen 'Process1_Initialization_Failed' error.

When I turned it off, as the Perfect Disk support suggested, it worked OK.

My laptop has it disabled because it has a Solid State drive. Usually the SSD firmware already compresses stuff that it deems appropriate, so this is quite understandable.

I guess if you have plenty of disk space, there's no good reason to turn this on. Performance probably won't improve - the file may be smaller, but the decompress takes longer.

I think this is one reason the Windows 10 startup time seemed to be getting longer - all those stuff getting decompressed...

EDIT: Perfect Disk just got updated to fix this problem.

 

Ran this last night on my 2-in-1 that has only a 32gb card as the primary. Gave me back 3gb of space after all the updates were ran, drivers installed, etc. Between doing a clean install to rid myself of HP bloat and compressing the OS I now have 16gb free. I flirted with removing IE and some other stuff, but there was no discernible difference. I'd love to get a couple more gb free. *Smile

 

Thanks a lot for this useful information! *Smile

[/quote] Can anyone please tell me how to use this code in a script with the compact command?

 

Hello Cloudtime, and welcome to Ten Forums. *Smile

Here's how in a command prompt for those.


Code: compact /c /s /a /f /q /i /exe:xpress16k %programFiles% compact /c /s /a /f /q /i /exe:xpress16k %programFiles(x86)% compact /c /s /a /f /q /i /exe:xpress16k %homeDrive%\MSOCache compact /c /s /a /f /q /i /exe:xpress16k %homePath%\Documents compact /c /s /a /f /q /i /exe:xpress16k %windir%\Assembly compact /c /s /a /f /q /i /exe:xpress16k %windir%\InfusedApps compact /c /s /a /f /q /i /exe:xpress16k %windir%\Installer compact /c /s /a /f /q /i /exe:xpress16k %windir%\Panther compact /c /s /a /f /q /i /exe:xpress16k %windir%\SoftwareDistribution compact /c /s /a /f /q /i /exe:xpress16k %windir%\System32\Catroot2 compact /c /s /a /f /q /i /exe:xpress16k %windir%\System32\LogFiles[/quote]