How-to: Quickly Reduce Windows Installation Size

Discussion in 'Windows, Linux & Others on the Mac' started by esaleris, Apr 6, 2006.

  1. esaleris macrumors 6502

    Oct 18, 2005

    As a current Windows user, I thought I'd shed some light on some things you can do to make your Windows installation smaller. Why is this important? Well, you can't really dynamically change the size of the partitions once you've committed the partitions in Boot Camp, and with many people playing games or trying out games, it's easy to run out of space.


    This guide is by no means complete, but it attacks the "low-hanging fruit" and allows you to slim down your install by perhaps 1 GB to 4 GB relatively safely, quickly, and easily. If you want a complete, albeit OCD and crazy guide (this guy tells you about every individual Windows file), visit This was the guide I followed, but I refused to go down to that kind of detail, so it was trial and error to see what mattered to me. I have reformatted Windows machines hundreds of times, and follow this procedure myself; however, I cannot take no responsibility for loss of data or whatever may happen to your machine!


    1. NtUninstall (100 MB). These are the uninstall files for all the fun Windows Updates. Why you'd want to uninstall a security patch or a bug fix is beyond me and I've personally never had to uninstall an update before. $MSI31Uninstall is also okay to delete, but do not delete $hf_mig$

    2. Precompiled Setup Files (30 MB). These files are cached versions of all Windows .exes plus every single .exe you have run since you installed Windows. I don't use half the .exes in there, so I don't need the cache around; and if I do run the program, it will create it on first instance, so no problem.

    3. Software Distribution (300 MB). This is the temporary installation folder for Windows updates. There is no reason to keep them, as they aren't even used in the uninstall process for Windows updates. It was pretty hefty on mine.

    4. dllcache (400 MB). This folder contains backups for all the system files installed on your machine. The folder allows the system to quickly restore files that are overwritten either by accident, bug, or virus/trojan. However, if you do not keep these files on your machine, then Windows will prompt you a Windows XP setup disc if some system file is being overwritten that it is monitoring. So I delete this huge folder and let my Windows CD house the backups.

      This is a nice feature, especially if you are worried about security, so delete at last resort. I only mention it becuase it's a hefty 400MB or more and could really help out some people. It is hidden, so go to the below folder directly from the "Address Bar" in Windows Explorer:

    5. Hibernation (~1 GB+). If you've got lots of RAM - say 2GB - and turn on the hibernation function, your hibernation file will take up that amount (in this case 2GB).
      Start > Control Panel > Power Options > "Hibernate" tab > Uncheck box.

    6. Page File (~1.5 GB+). Same thing applies to your page file, as Windows, by default, sets your page file to be dynamically size between something like 1.5x your RAM to 2x your RAM. It should be safe to reduce the page file to 1GB. I wouldn't recommend putting it on an external drive.
      Start > Control Panel > System > "Advanced" tab > "Performance Settings" button > "Advanced" tab > "Change" button > Enter size and press "Set."

    7. System Restore (~1.0 GB+). Windows has this feature called System Restore, that keeps track of any installations, in case you would like to roll-back before a bad driver or program installation. However, for dual-booters who are just installing games, it hardly seems necessary to keep 10-20% of your hard drive available to back up your system before a game installation. You can either decide to let this service take up less space, or disable it altogether. I've disabled it, since I'm pretty careful of what I begin installing on my machine.
      Start > Control Panel > System > "System Restore" tab > Either uncheck "Turn off System Restore..." or set % of drive space to use.


    I hope this has been helpful. Any comments are welcome and I'll be glad to update if you think there's another "low-hanging fruit" folder that can easily be deleted for quick recovery of HD space.

  2. /dev/toaster macrumors 68020


    Feb 23, 2006
    San Francisco, CA
    This is a very nice guide. Beyond my MBP, this will be pretty helpful.
  3. esaleris thread starter macrumors 6502

    Oct 18, 2005
    /dev/toaster (or anybody),

    Just wondering, do you by default, whether or not hiberation is enabled?
  4. Morn macrumors 6502

    Oct 26, 2005
  5. esaleris thread starter macrumors 6502

    Oct 18, 2005
    The Mac one is simple. Don't install the language translations and the printer drivers when you install OS X. :D
  6. balamw Moderator


    Staff Member

    Aug 16, 2005
    New England
    I have yet to see a Windows installation from generic install media where hibernation was enabled by default. There may be some laptops where it is enabled by using the "rescue disk", but not from retail or generic OEM install media.

  7. esaleris thread starter macrumors 6502

    Oct 18, 2005
    You're right, my bad. As you can see from my sig, I have a Thinkpad and as part of the process to roll out all the IBM/Lenovo drivers, I install a power management tool that enables Hibernation.
  8. Whiteapple macrumors regular


    Jan 17, 2006
    Haute Savoie,France
    I saw something crazy...true hibernation works...!!11!
    What I mean is, I thought you wouldnt have the "computer breathing-led" stuff elsewhere than on OSX, alongside with the instant wake up time I get on the macbook. Installed xp, and then gave it a go. Exactly like OSX!! Wakes up instantly, not even the loading stuff, instant!.
    However, I dont yet know how to disable the "you have to click on your session icon to go back into windows" function. Amazing, but what a deception at the same time. Hardware/Software? Hard to tell
  9. esaleris thread starter macrumors 6502

    Oct 18, 2005
    Windows Hibernation works as follows: The entire contents of RAM is put onto the hard drive. And the machine shuts down. When the computer starts up, it loads that data into the RAM.

Share This Page