Unknowingly to many Windows 7 users, a hidden primary system partition which is active will be automatically and forcefully created by setup during installation of Windows 7. The additional separate standalone NTFS partition, which is not labeled with any drive letter or path, has the size of 200 MB, but only occupy 32 MB of it with 168 MB remains free.

Windows 7 200MB System Partition

The small 200MB partition actually holds Windows Recovery Environment (WinRE), which only available from DVD installation disc in previous operating system such as Windows Vista (see how to launch WinRE on DVD). The partition holds system files and bootable files that are essential to boot the Windows 7 properly in the event of the need to recover the OS in the event of corruption. The 200MB partition is pretty much similar to many recovery partition that been made on factory installation by most OEMs on the computer they sold.

However, when the small 200 MB separate partition has been created by Windows 7, it’s almost impossible to be deleted or removed. User cannot use delete the volume using Storage Disk Management in Computer Management. If forcefully deleted with third party partition manager or partition editor, Partition Table which is (normally) located in the master boot record (MBR) may be corrupted, or may become invalid.

The cause for the Partition Table error is because the 200MB partition does not use the standard sector zoning format. When deleted with partition tool which does not support non-standard partition type, the Partition Table will be corrupted. When the Partition Table is corrupted, the third party partition editor will show disk partition error has occurred on any re-created partition that uses the freed space (Disk Management in Win 7 do not show the error though). And the hard disk tends to have unallocated disk pace of 1 to 2 MB in size randomly. Format the hard disk volume or partition cannot fix the error either. In worst case scenario, some partition may be lost occasionally, causing files or data lost.

For Windows 7 users who don’t want the 200MB partition to be created and existed, the best way is to stop Windows 7 installation process to create the partition when installing Windows 7. In Windows 7, the feature (200 MB partition to store WinRE files) is installed on all computers if the OS is installed on hard disk with single partition scheme, or unallocated space (space which not yet been partitioned) on the hard disk drive.

Thus in order to skip or avoid the 200M partition to be automatically created during installation, here’s a few rules to follow when choosing where to install Windows 7 to:

  1. Do not install Windows 7 to a hard disk that not yet been partitioned or to unallocated space (When install Windows 7 to unallocated space, no warning pop-up or confirmation is asked, and setup will straight away and directly create partition 200 MB of disk space as special partition without notification).
  2. If possible, try to create all the necessary partition(s) and format the partition(s) before attempting to install Windows 7.
  3. If you’re installing Windows 7 into a new hard disk, or a blank hard disk with no partition defined yet, or if you must delete all existing partitions to start afresh, chose Drive options (advanced). Delete (if applicable) unwanted partitions. Then, click New to create the single partition or multiple partitions according to your own preference.

    Windows 7 Additional Partition During Installation

    When prompted with dialog box saying “To ensure that all Windows features work correctly, Windows might create additional partitions for system files”, click on Cancel button. Optionally, to be double confirm, Format the partition before selecting it to install Windows 7.

When Windows 7 does not create the special 200MB partition, the WinRE recovery environment is stored in a folder in the root of Win7 installation drive. For example, if Windows7 is installed to a partition with a label of C:, the WinRE will be located located at C:Recovery.

Note: The hidden system reserved partition size is 100 MB in Windows 7 RTM, and the trick to prevent and remove 100 MB system reserved partition has been changed.

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  • anuj

    Oh Yaar kam se kam 500 gb hdd k jamane me 200 mb space bachana! kis yug me ho bhai log its very very essential to run properly and fast windows.

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  • ???

    Installing win 7 on usb drive will keep this from happening

    for info on that google bootable usb drive

  • WhitePaw Rolls

    Ok for those wanting to do without this partition I have discovered a few more facts you might want to think about. the new sp1 will NOT install without it. The genuine advantage thingy don't like it not being there, and without those 2 you can't use xp mode. I found this out the hard way after doing the install without the partition, and had to reinstall WITH it to use those things.

  • Peter57

    There is another good reason for deleting the 200MB partition. As a policy I have always had three drives on my computer to separate the OS from my data and source CD-ROMs – C: for the system files, D: for my data files, and K: for copies of the major applications CD-ROMs which I use in cases I need to fix or modify the installed applications.

    My brand new Dell 37500 notebook came with three partitions on the HDD – the 200 MB, the primary partion with the OS, and a hidden Recovery partition. I added a new partition (#4) for data, but I was unable to add yet another partion (#5) for the CD-ROM copies.

    It turns out that in Windows 7 there is a limit of maximum four (4) partitions on a single physical drive, and obviously there is no provision for a second HDD in a notebook.

    Then I installed a brand new unformatted 750 GB drive, installed Win7 from a CD, and yes, there was the 200MB partition again. For some good reason I decided to reinstall the Win7 again, but first I partitioned and formatted the drive outside the notebook in a USB enclosure. Then I put it into the notebook, installed Win7, and voila, no more 200 MB partition. The OS works as it should, and I have all the usual partitions I need.

    The article above finally explained why and how I unwittingly got what I wanted. Thanx.

    • CDF

      Peter57: You don't understand how to partition for Windows correctly.

      To clarify – the reason you couldn't add a "5th" partition to your Dell is because you were trying to add a 5th PRIMARY partition. Any Windows OS (in general), only allows 4 Primary partitions; since there were already 3 existing on your Dell, you created the 4th allowable for your D: partition.

      If you need to have more than 4 partitions for windows, you would have to create an Extended Partition for space after the existing partitions, then created Logical Partitions D: and K: within the Extended Partition. You can created as many Logical partitions as needed (in general) within the Extended partition.

  • Jerry O.

    Re: Ohooooh, 10-Oct-2009, It's not the government that's spying on you, it's the little green big-eyed aliens, whose brothers-in-law are in suspended animation at Area 51, and who have abducted Elvis, (who is still living) in their big, grey flying saucer, who are spying on you. Stop being so paranoid, for god's sake. There may be a sinister reason for this (like discouraging dual-boot open-source OS's, but more likely just a perhaps arguably stupid reason, at worst. The gov't(s) hasn't/haven't the time or money to catch all the actual criminals, never mind spy on any idiot using a computer to surf Facebook. Even the Communists and tin horn dictators targeted people based on actual, if unfounded, suspicion of subversion.

    • Martin

      Dude, the issue is unwanted disk usage reserved for unused space. Read the thread first before you make brash comments.

      • Jeff W.

        Assuming a 500gb system drive (which is kinda low on a modern system), a 200mb recovery partition is 0.04% of the total space on the drive.

        Are you really so worried about 0.04% of your hard drive space that you are willing to try some convoluted workaround to get it back? You lose more space than that if you choose a slightly less than ideal block size when you format the drive (and you probably can’t tell your choice was less than ideal).

        It seems a little silly to me, but more power to you I guess.

  • steward

    never do any work on that 200mb hidden partition.

    For my idea, we shouldn't do any changes on our hidden partition

  • Mike Lazur

    If you're worried about 200MB then maybe you should invest in a larger capacity hard drive.

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  • x0fx3

    I clicked cancel like your instuctions says and it doesn't create my partitions. i'll have to use gparted I guess.

  • Fahad Mehar

    I want to remove System Reserved Please tell me how ? :/

  • Risvi

    "Extend" the 100/200 MB drive to your desired size. then make other partitions. Thats all.

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  • Another one for dumm

    Win7 Ultimate installer. If you hit Cancel in the "…Windows might create additional partitions for system files" dialog, it just does nothing — doesn't create any partitions, the drive stays entirely unallocated. I can only hit OK in that dialog, which creates the System Reserved partition and the main partition, and only then delete the System Partition. I found no way at all to use the entire drive space for the main partition — the 100MB from the deleted System Reserved partition just stays unallocated. And that's "advanced" partitioning options WTF!

  • Bannor99

    I'm pretty sure that you won't have a problem putting Linux swap or even Linux root on an logical partition.

    If I recall correctly, that has been possible for more than a decade.

  • Jawad Hussain

    how are you. I hope you are fine and in good health. i installed win xp on windows 7 and i faced a couple of problems. First is i cannot boot windows 7 now as the system by defaults boots from xp. Another problem is i am seeing a drive named System reserved (C:) which is of 100 MB. Now according to the person from whom i bought by new Lenovo G550 laptop he installed a pirated windows 7. i also know that windows 7 created a 100 MB partition so whenever i try to install any driver it says that not enough disk space on C. Free some diskspace which makes sense as 100 MB is nothing. I hope u get my point. Before installing Xp i was seeing three drives i-e C, D and E but now i am seeing C, D , E and F and F is the drive on which i installed the windows xp. Please reply ASAP

    Thanks for replying in advance


    Allah Hafiz

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  • Stephen De Groot

    You think that by creating a second hidden partition it would create the perfect hiding place for a virus that most of the more non-technical users would not be aware exists?

  • Trying to help out

    @Tom Dietrich

    It's not required to install Mac OS X on a primary partition. I've installed it on a logical partition. You use a file called tboot instead of chain0. Just research it, it might solve your problem.

    And using the GUID partitioning mechanism, you can create more than 4 primary partitions on a single drive.

  • Ollie Treend

    This is actually slightly concerning…

    I somehow managed to delete my system reserved partition WITHOUT causing any errors or partition corruption.

    But now I don't have a copy of the WinRE in case anything goes wrong… it's not in my C: drive since Windows put it on the separate partition.

    Ah well… fingers crossed. I don't mind re-installing if anything goes wrong. I keep backups of my files anyway.

  • Tom Dietrich

    This is a pain in my neck. My first installation of Windows 7 didn't have this trouble because I had pre-partitioned my drive. When I got a new drive and did a fresh install I allowed Windows to auto-partition during the install, not realizing it would create this "System Reserved" partition.

    To the people complaining about it being placed on their IDE drives: that's your own fault. The partition is placed onto your FIRST BOOT DRIVE as defined in your BIOS. If you had been smart enough to adjust your BIOS before you installed Windows then it would have been placed on your SATA drive (like mine was) or on whatever you define as your first boot drive in BIOS.

    Now, to answer all the questions about why I don't want this. It's not because I'm a Microsoft hater. I'm very fond of Microsoft products, and make my living off of them. However, the problem I have is that this is created as a PRIMARY partition, and then Windows 7 is installed to another PRIMARY partition. That takes up 2 of my allowable 4 PRIMARY partitions. So, I then install Ubuntu, which creates a PRIMARY partition for the installation, and then another PRIMARY partition for the SWAP space. BAM! All 4 used up. Now I cannot install my copy of OS X because that also needs a PRIMARY partition. Good thing my copy of Vista is on a separate hard drive.

    Looks like I'll be doing some research to change my Linux SWAP partition to EXTENDED…

    • Jeff W.

      This is the only reasonable reason for doing this that I’ve seen so far.

      A solution for you may be to set up the drive as GPT instead of MBR – pretty much all modern drives are capable of this.

      GPT can have 128 primary partitions, and unlike MBR is capable of booting from drives larger than 2TB.

      Windows has been capable of using GPT since 2000, so I have no clue why the hell we still mess with MBR. It doesn’t make any sense, really.

      See this link for instructions on converting an MBR to a GPT disk: http://technet.microsoft.com/en-us/library/cc725671.aspx

  • Seth


    I bought a new HDD, installed it with my old HDD still in and installed a clean copy of Windows 7 on my new HDD. Since this stupid thing fucked up and automatically installs all of the fucking boot information onto the first IDE drive it installed it on my old HDD, so now that I have all the data on my new HDD I can't reformat my old one since IT'S BOOTING OFF OF IT.


  • Rhy

    ugh, this is when windows-hater's become annoying. Seems people will whine about anything microsoft do now.

    i highly doubt an extra partition (even with such a MASSIVE size as 200mb) can really break your computers as much as some will complain, if at all.

    • waynebaal

      The main reason is, as has been mentioned before, that it takes up one your four allowable primary partitions….and for no reason, unless you use Bitlocker (this is where Bitlocker informatio is stored).

  • Sylvain

    Q: what possible reason could you have for not wanting it and the benefits it provides?

    Some peoples are running more that Windows…

    and want more control over their O/S…

  • Stevedeeg

    What I do find odd is that the hidden partition is automatically installed on the first IDE drive, regardless of what HDD your main partition is installed on. It is an annoyance when you are using mobile HDD racks.

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  • Oh hooooh

    So windows 7 creates a "secret" 200MB partition which is designed to prevent your access to it. Why whould anyone go to all this trouble? it makes no sence, but it does if you put yourself in the designers shoes.

    As MS are the chaps who make win7, start looking at them, ask yourself, why would they do this to your computer hard drive in secret.

    Is it possible they want a secret area of your hard drive setup so they can place in this secret area secret software or several secret tools to prevent you from returning your PC to a known "unsecret" previous condition?

    Is there going to be any "spying activerty" done by them or government agency that can run a special system command to access your PC without you being the wiser of it?

    Say you decide to remove a security update file in windows, reboot and the internal OS does a sys check, finds you have removed a file, it might be able to "replace" that file autimaticly.

    MS could even setup special software to be enabled by a hidden command from them or a gov agency, how would we know this hidden partition was being used honestly?

    Well "secret" hidden partitions, created at system creation, smell big brouther trouble to me big time.

    Keep your XP or W98 install cds, for emergency.

  • Jordan Borean

    The best way to not install this is to create a partition, delete the non 100MB 1 and the extened the 100MB onto the larger one and that creates one whole partition.

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  • Anon


    Many programs require the first partition to be the OS containing partition. eg: whole drive encryption programs.

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  • It doesn't bother me that it creates a partition, it bothers me that it sues 2 primary partitions allowing only 2 additional operating systems to be installed, or a dual boot with a dedicated boot partition. It would be better if it put Windows 7 in a Logical Partition inside an Extended. That way you can expand the extended and keep more Primaries.

  • fyrekrig

    I followed you instruction but still a 100MB partition is created!

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  • T


    Many who do this do it for a reason. Mine personally is for Truecrypt full disk encryption. Bitlocker doesn't work on machines without the TPM, I think it is, and if you use a work around you're likely run into other problems.

  • Kevin

    Other operating systems (linux, BSD) create a root partition. However, unlike Windows 7, they don't hide it from the computer owner. Saying that it's used for recovery is a false pretense.

    A simple solution would be to provide end users with a live CD, similar to those used to repair linux systems.

    I wanted to try Windows 7 but now I think I'll pass. I don't have time for such nonsense.

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  • i too have the 200 mb allocation.(Win7 install) I was a first time raid installer. I thought i screwed it all up. Glad it wasn't me. thanks, RF

  • Ralph Montgomery

    A very good reason is you are unable to complete whole disk encryption with Truecrypt when this partition is created.

    Thus, all the work to this point I have accomplished is for naught.

    Time to ERASE and install the way I WANT TO, not MS.

  • dwindle

    Why on Earth would you be concerned about such a puny amount of hard drive space?

  • IF you guys are going to be so purdnet why even bother testing windows 7! That 200mb partion is not only a wast of space 200mb and it only use a fraction of the space. It also hinders you from installing vista for a dual boot because that said partion is to bloddy small, vistsa needs 392mb of free space temp space and it auto uses the 200mb pariton so no vista for you.

  • Anthony

    Why would you NOT do this? Because Windows 7 is still in Beta. Good idea when the OS has matured to RTM.

  • Deep Debroy

    The 200 MB Partition is your ACTIVE partition. As you correctly found out, it hosts your BCD/BootMgr/etc. When you start Windows, first the BootMgr gets loaded from the System Partition and then it goes ahead and loads the overall OS from other bigger partitions.

    Since this partition is needed for booting your OS, the OS takes certain steps to make it hard for you to delete it since allowing you to format or delete it would render Windows 7 unbootable.

    NOTE: this has nothing to do with recoverability. It is highly discouraged that you don't put additional stuff in that partition either.

    • admin

      The 200 MB is ACTIVE, but NOT BOOT partition as far as I know. It's WinRE boot partition to boot Windows 7 in case of real boot partition corrupt.

  • Why would you do this?

    The boot partition is created for a reason, what possible reason could you have for not wanting it and the benefits it provides? (better recovery, ability to wipe the OS partition without messing up dual boot setups, ability to enable Bitlocker, and more).