Computer and Software Support


Running 32-bit and 64-bit snap-ins in Windows Server 2003 and Windows XP Professional operating systems

This page is from Microsoft

Updated: January 21, 2005
 

Running 32-bit and 64-bit snap-ins in Windows Server 2003 and Windows XP Professional operating systems

The 64-bit versions of the Microsoft® Windows°Server™°2003 and Microsoft® Windows®°XP Professional operating systems can run both the 32-bit Microsoft Management Console (MMC32) and the 64-bit MMC (MMC64). MMC32 can run only 32-bit snap-ins, and MMC64 can run only 64-bit snap-ins. However, some snap-ins are available in both 32-bit and 64-bit form. A snap-in is considered available in 64-bit form if it defined by an HKEY_CLASSES_ROOT\CLSID\snap-in clsid\InprocServer32 key in the registry, where snap-in clsid is the registered CLSID for the snap-in.

This topic describes how to determine and control which version of MMC is run in 64-bit versions of Windows operating systems.

Start-up considerations if /32 or /64 is specified

MMC can be run from the command line by using a command such as the following that includes a console file name:

%systemdrive%\Documents and Settings\username\Start Menu\programs\Administrative Tools\myconsole.msc

On the 64-bit version of a Windows operating system, you can include one of the following command-line parameters:

/32
Specifies MMC32.
/64
Specifies MMC64. This is the default on the 64-bit version of a Windows operating system.

If both of these command-line parameters are used, the last one on the command line takes effect. MMC64 yields transparently to MMC32 if certain conditions are met, as described in the following section.

Start-up considerations if a console file is specified

If the command for running MMC does not contain a /32 or /64 parameter, but does contain a console file name, MMC64 examines the console file before determining which version to run. The decision sequence is as follows:
  1. If all snap-ins in the console are available in 64-bit form, MMC64 is used.
  2. If all snap-ins in the console are available in 32-bit form and some are not available in 64-bit form, MMC32 is used. (MMC64 starts MMC32, and then MMC64 terminates.)
  3. If some of the snap-ins are available only in 64-bit form and others are available only in 32-bit form, the version of MMC that can run the majority of the snap-ins is used. The remaining snap-ins are not loaded.

    For example, if a console contains three snap-ins that are available only in 32-bit form and two snap-ins that are available only in 64-bit form, MMC32 is used and only the three 32-bit snap-ins appear when the console is opened. The two snap-ins that are available only in 64-bit form would not be loaded.

  4. If some of the snap-ins are available only in 64-bit form and an equal number of snap-ins are available only in 32-bit form, you will be prompted to specify which version of MMC to run. If you choose MMC64, only the 64-bit snap-ins are loaded. If you choose MMC32, only the 32-bit snap-ins are loaded.

When to specify the path to the console file

In Windows XP and Windows Server 2003 operating systems, the system files are stored in the %windir%\system32 folder. In the 64-bit versions of these operating systems, the \system32 folder contains 64-bit files, including 64-bit consoles such as eventvwr.msc. If there is also a 32-bit version of the snap-in, it resides in the %windir%\syswow64 folder. In this example, the 32-bit version of Event Viewer would be %windir%\syswow64\eventvwr.msc.

If there is both a 64-bit version of the console in the \system32 folder and a 32-bit version in the \syswow64 folder and you want to explicitly run the 32-bit version, you must bypass the MMC decision-making process by specifying both the path and the /32 command-line parameter. For example:

MMC /32 %windir%\syswow64\eventvwr.msc

Note

  • Double-clicking a shortcut to a file in the \syswow64 folder is like double-clicking the file in Windows Explorer: it will run MMC without the /32 command-line parameter. To open the 32-bit consoles in the \syswow64 folder, click Start, click Run, and then type the command specifying both the path and the /32 command-line parameter, instead of using a shortcut.