I've got a DVD that I've burnt from an MSDN ISO. I'm not entirely sure if its Windows 7 64bit or 32bit.

How can I be sure?

  • If you are unable to see the file name, try booting from the disk and scroll through the EULA because there is an ID at the top of the bottom of it that could contain more information. Sep 17, 2010 at 9:30
  • Possible duplicate of superuser.com/questions/121828/…
    – MartW
    Sep 17, 2010 at 11:28

9 Answers 9


Quickest way is to go to the drive root. If you have a file named Bootmgr.efi you are running a X64/64-bit version.

Next way is disk size, the x86/32-bit version comes out at ~2.32GB whilst the x64/64-bit version comes out at ~3.0GB.

Lastly, you can go to the drive root and open the autorun.inf file.

In notepad, the 64 bit version shows:


open=sources\sperr32.exe x64

The 32 bit version shows:

  • not sure about that bootmgr.efi thing being just for 64bit, as I have it on a 32bit version. I have the 32bit version as I see from autorun.inf and from the dism command in the other answer.
    – barlop
    Sep 19, 2017 at 22:01
  • @barlop actually may have been win10
    – barlop
    Sep 20, 2017 at 13:24

Best and quickest way to answer the question about both Processor architecture and Windows version is:

Use DISM on install.wim.

  1. Click "Start", type "cmd", press "ENTER".
  2. Type or paste: dism /get-wiminfo /wimfile:"f:\sources\install.wim"
    (Replace f: with drive path to installer root).

Deployment Image Servicing and Management tool

Version: 6.1.7600.16385

Details for image : f:\sources\install.wim

Index : 1 Name : Windows 7 Ultimate Activated 32Bit
Description : Windows 7 ULTIMATE Size : 8,476,902,704 bytes

Index : 2 Name : Windows 7 Ultimate Activated 64Bit
Description : Windows 7 ULTIMATE Size : 12,075,969,989 bytes

The operation completed successfully.

  1. Windows version is on the second line. First two dot pairs are OS version. Third and fourth dot pairs are Service Pack and Build info. See Windows Version Numbers to lookup your version.

  2. Processor architecture is explicitly shown in the remainder of the WIM info. In this case, this is a dual installer for both 32 bit and 64 bit processors, for Windows 7 Ultimate.


To know wich edition see the ei.cfg file located in the Sources directory on the installation DVD


The way would be to see if the disk contains x64 images. Just looking at an MSDN Windows 7 Ultimate x64 DVD and I see the file <DVD>:\sources\actionqueue.dll is x64.

To check that it is x64 I used dumpbin /headers <file> (dumpbin is a Windows SDK tool):

Microsoft (R) COFF/PE Dumper Version 10.00.30319.01
Copyright (C) Microsoft Corporation.  All rights reserved.

Dump of file .\actionqueue.dll

PE signature found

File Type: DLL

            8664 machine (x64)
               5 number of sections
        4A5BE044 time date stamp Tue Jul 14 02:32:52 2009
               0 file pointer to symbol table
               0 number of symbols
              F0 size of optional header
            2022 characteristics
                   Application can handle large (>2GB) addresses

Note highlighted line (a x86 executable would have 14C machine (x86)).

I can't see any file that lists the bit-ness directly, so this is the quickest way (if you have the SDK tools). Might just be easier to burn a new DVD from the required ISO.


If you have administrator access to a system already running Windows 7 (this feature is not in Vista):

  1. Open a command prompt as an administrator
    • Start, cmd, Ctrl+Shift+Enter
  2. Insert the Windows 7 DVD, and close any autoplay popup.
  3. Type dism /Get-WimInfo /WimFile:X:\sources\boot.wim where X is your DVD drive's letter.
  4. You should see something like the following:

    Deployment Image Servicing and Management tool Version: 6.1.7600.16385

    Details for image : h:\sources\boot.wim

    Index : 1
    Name : Microsoft Windows PE (x86)
    Description : Microsoft Windows PE (x86)
    Size : 806,390,831 bytes

    Index : 2
    Name : Microsoft Windows Setup (x86)
    Description : Microsoft Windows Setup (x86)
    Size : 881,382,947 bytes

    The operation completed successfully.

If your disk is 32-bit, it will look like above where it says (x86). If it's 64-bit, it should say, (x64).

If you don't have a computer with Windows 7 already installed, then try installing the operating system in a virtual machine such as VirtualBox. This should work on any computer, even a Mac. If it fails, then you have the 64-bit version and your computer doesn't support/have enabled Hardware-accelerated virtualization. If it installs successfully, then check the System Properties inside the virtual machine.

If you don't want to do that, then download and burn the Windows 7 Automated Installation Kit, and install it (it will work on Vista SP1 or newer). Be warned, the download is 1.7GB, so it's not exactly the ideal way to check this if you have a slow or metered internet connection. Once you have the WAIK installed:

  1. Open the Deployment Tools Command Prompt as an administrator.
    • Start, Deployment Tools Command Prompt, Ctrl+Shift+Enter
  2. Insert the Windows 7 DVD, and close any autoplay popup.
  3. Type: imagex /info X:\sources\boot.wim where X is your DVD drive letter. If the output contains the line <NAME>Microsoft Windows PE (x86)</NAME>, then it's 32-bit. If it says (x64) then it's 64-bit.
    • Alternatively, type imagex /info X:\sources\install.wim, and check for a line starting with <ARCH>. If that line lists <ARCH>0</ARCH> then it is 32-bit, otherwise it is 64-bit.
  • is there any variation that tells you if it's home or pro?
    – barlop
    Sep 20, 2017 at 13:26

If you get a listing of the root directory on your installation disk, you can see difference in filesizes:

  • Only in the 64 bit version there is bootmgr.efi file
  • The 64 bit has an autorun.inf filesize of 122 bytes and 32 bit autorun.inf is 43 bytes.
  • The 64 bit has a setup.exe filesize of 106,760 and 32 bit setup.exe is 111,880.

At least, that's what I have for the downloaded/original ISOs from the Microsoft Store.


This solution also works well if you have an iso file saved in the hard drive. Below are the instructions:

First you need to mount the ISO file to a computer so you can browse it.If you have a DVD as a installation medium,then just simply click on the DVD drive.Then open up a command prompt as administrator and run the following command (note that 'E' is the drive letter for the mounted ISO file here).

dism /Get-WimInfo /WimFile:E:\sources\install.wim /index:1

This will display full details of the built number, architecture, version as well as many other important details for your convenience. The following is an example output from Windows Server 2016.

Index : 1
Name : Windows Server 2016 Standard
Description : This option (recommended) reduces management and servicing by installing 
only what is needed to run most server roles and applications. It does not include a 
GUI, but you can fully manage the server locally or remotely with Windows PowerShell 
or other tools. For more details see "Windows Server Installation Options."

Size : 9,353,610,808 bytes
WIM Bootable : No
Architecture : x64
Hal : acpiapic
Version : 10.0.14393
ServicePack Build : 0
ServicePack Level : 0
Edition : ServerStandard
Installation : Server Core
ProductType : ServerNT
ProductSuite : Terminal Server
System Root : WINDOWS
Directories : 14199
Files : 67418
Created : 11/20/2016 - 10:57:52 PM
Modified : 11/20/2016 - 10:58:21 PM
Languages :
        en-US (Default)

The operation completed successfully.

Best way for checking is Go to drive.../efi/boot/

If bootai32.efi or bootai86.efi or bootx32.efi or bootx32.efi is present, OS is 32bit.

If bootax64.efi or bootai64.efi is present, OS is 64 bit.

Hope this helps.




If the program is an ISO file, open it, find the Setup.exe file. right click brings up a menu, select More, then list all. This will load all packets to install. Look at the name of the packets. look for i386 as part of the name of the files. i386 is 32 bit architecture.

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