Windows 10: Compress or Uncompress Windows 10 with Compact OS  

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  1.    28 Nov 2015 #10

    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.
    Last edited by arachnaut; 30 Dec 2015 at 18:01.
      My ComputerSystem Spec

  2.    30 Dec 2015 #11

    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. :)
      My ComputerSystem Spec

  3. Posts : 4
    Windows 10 (Tablet only)
       23 Apr 2016 #12

    Thanks a lot for this useful information! :)

    lx07 said: View Post
    If your interested in saving more space I've also compacted these directories with compact /c /s /a /f /q /i /exe:xpress16k

    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.

    Can anyone please tell me how to use this code in a script with the compact command?
      My ComputerSystem Spec

  4. Posts : 30,586
    64-bit Windows 10 Pro build 17713
    Thread Starter
       23 Apr 2016 #13

    Hello Cloudtime, and welcome to Ten Forums. :)

    Here's how in a command prompt for those.

    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
      My ComputersSystem Spec

  5. Posts : 4
    Windows 10 (Tablet only)
       23 Apr 2016 #14

    Very awesome, thanks a lot for your super quick response It's working like it should.
      My ComputerSystem Spec

  6. Posts : 30,586
    64-bit Windows 10 Pro build 17713
    Thread Starter
       23 Apr 2016 #15

    You're most welcome. :)
      My ComputersSystem Spec

  7. Posts : 31
    Windows 10 Home 64-Bit Version 1709 Build 16299.125
       16 Aug 2016 #16

    Just some info regarding the performance impact that CompactOS has on my own system:
    On my Samsung 840 EVO 120GB SSD when I clean installed Windows 10 it has always been in the non-compacted state. After the Anniversary Update, it automatically changed to the compacted state for unknown reasons. I had to re-tweak a lot of settings in Windows 10 as each major update is almost essentially a new install all over. Everything seems to been fine, even my boot time seems a bit faster. Except for my shutdown time - it went from 5-6 seconds (with hibernation and fast startup disabled) to 11+ seconds. Just a moment ago I confirmed my theory that the cause of the longer shutdown was due to CompactOS by turning it off. Low and behold it changed to 2 seconds! My boot time remains the same, and my OS drive space usage only increased by around 1.5 to 2 GB. I'm keeping it uncompressed since I don't notice any difference in daily performance.

    Results obviously vary between systems.
      My ComputerSystem Spec

  8.    17 Aug 2016 #17

    Just noticed that the Anniversary update changed my compactOS setting (which was 'never').
    Apparently, 'never' means 'until we meet again'.

    So, I needed to run this again:

    ADMIN>compact /compactos:never

    Technically, it wasn't compacted because this is the command sequence I saw/executed:

    C:\WINDOWS\system32>compact /compactos:query
    The system is not in the Compact state but may become compact as needed.
    C:\WINDOWS\system32>compact /compactos:never
    Completed uncompressing OS binaries.
    0 files within 14484 directories were uncompressed.
    C:\WINDOWS\system32>compact /compactos:query
    The system is not in the Compact state.  It will remain in this state unless an
    administrator changes it.
    This tends to make me wonder just which version of Windows updates will change the OS properties that are set in the prior version?

    In other words, it isn't Windows 10 anymore, just a newly visited Windows.
      My ComputerSystem Spec

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