In Windows 7, it seems it's only possible to view a file's version number in the Properties dialog if it is a .dll/.exe file; if the file name extension is .ax, it won't show the file's version number.

Are there any settings I can change to enable this for .ax files?

  • What exactly is this .ax file type?
    – Jay Wick
    May 13, 2010 at 9:57
  • @jay: It's a DirectShow filter (codec), internally just an ordinary Windows library. May 13, 2010 at 11:53
  • 1
    It's strange Win7 doesn't show version numbers. In XP, the 'Version' tab is displayed regardless of what extension the file has, as long as it's a Win32 executable... May 13, 2010 at 11:54
  • Oh I see, so AX is just a container extension?
    – Jay Wick
    May 13, 2010 at 12:01
  • 1
    @jay: It's not a container. It's just an ordinary Windows DLL, which conforms with the DirectShow requirements (ie. has functions to encode video data or something). May 13, 2010 at 14:57

6 Answers 6


The Windows executable formats (which are in files with the EXE and DLL extensions, among others), have the ability to hold that metadata specially. For any other file type, that would require not only the file format to have that metadata, but for Windows Explorer to know how to get the metadata back out. For example, when you click on an ODT file in Windows 7, no information about the file will appear unless you have installed OpenOffice.org or LibreOffice, which register a component that Windows Explorer uses to be able to display information such as the document's author and title in the Explorer window.

  • 2
    (It might be possible to look in the registry to see if you can register the .ax filetype the same way that .exe is registered, so that Explorer will treat it as another executable. Then again, Microsoft may have intentionally removed such functionality; they have a long history of using the PE file format with different extensions and not letting you treat them as executables...) Jul 25, 2011 at 7:43

Just use this Shell Extension which which brings back the old XP version tab to Explorer:

Windows 7 File-properties "Version" Tab Shell Extension

Now you can see the file version information of .ax files.

enter image description here


The problem you raise is very mysterious.
I list below what I did, although without a real answer, just a conjecture.

As you say, "File version" is only displayed for .dll, never for .ax, although .ax stands for a dll that implements a codec.

I have renamed an .ax to .dll, and to my surprise found that "File version" was now displayed, where it wasn't before, both in Properties and in the pop-up.

Next stop was in the registry, trying to compare HKEY_CLASSES_ROOT\.dll with HKEY_CLASSES_ROOT\.ax. Another surprise : HKEY_CLASSES_ROOT\.ax does not exist.

Ah, ha! I immediately exported HKEY_CLASSES_ROOT\.dll, replaced all occurrences of dll by ax, re-imported back into the registry and verified the existence of HKEY_CLASSES_ROOT\.ax, now identical to HKEY_CLASSES_ROOT\.dll.

Result: Absolutely nothing. Explorer still refuses to display "File version" for .ax.

One more : To try to force Explore to display "File version", right-click its column-headers, choose "More..." and check "File version" . Result: Version is not displayed for an .ax unless it is renamed to .dll or .exe.

The only conclusion I can offer, is that the display of "File version" is built into the Explorer program itself for well-known executable file-extensions, which are only .dll and .exe.

When making up this list, Microsoft unfortunately totally forgot about .ax, and also all about .scr (dll used for screen saver).

(All testing was done under Windows 7.)


I don't know if it'll work with .ax files, but Sigcheck from Sysinternals is what I use to display executable (exe/DLL) version and description from command prompt. Try it, it's only 114KB.

Sigcheck works with .ax files, too. Sample output:

sigcheck -a CoreAVCDecoder.ax
Sigcheck v1.71 - File version and signature viewer
Copyright (C) 2004-2010 Mark Russinovich
Sysinternals - www.sysinternals.com

C:\Program Files\CoreCodec\CoreAVC Professional Edition\CoreAVCDecoder.ax:
        Verified:       Unsigned
        File date:      1:26 AM 12/19/2009
        Publisher:      CoreCodec
        Description:    CoreAVC DirectShow Video Decoder
        Product:        CoreAVC Video Decoder
        Version:        2.0.0
        File version:   2.0.0
        Strong Name:    Unsigned
        Original Name:  CoreAVCDecoder.ax
        Internal Name:  CoreAVCDecoder
        Copyright:      Copyright ⌐ 2005-2009 CoreCodec, Inc.
        Comments:       http://www.coreavc.com

Edit 2:
Just to be clear, not all DLL/Exe contain WinPE resource block where version information is stored. If that's the case, you won't see 'Version' tab for those files. You can use Sigcheck to confirm this. If Sigcheck can't display version information of a file, it means that particular file does not have a proper resource block.


Windows Explorer refuses to extract information from the file format, even after changing HKEY_CLASSES_ROOT\SystemFileAssociations\.ax!FullDetails to force the file version property to appear on the details tab.

Looks like you need a third-party property handler for the file type or a shell extension that display the information elsewhere (preview handler, property sheet handler etc). The one suggested by magicandre1981 is such a property sheet handler.

  • 1
    This answer does not contain any new information.
    – harrymc
    Feb 27, 2013 at 8:12

You should not only copy HKEY_CLASSES_ROOT\.dll (and rename respectively). You also need to copy and rename key HKEY_CLASSES_ROOT\SystemFileAssociations\\.dll.

  • Almost forgot! This key too: [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\PropertySystem\PropertyHandlers\.dll]
    – Valentin
    Jul 30, 2014 at 15:36

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