What is an XNK File?

How to Open/Use XNK Files & Make them Work in Newer Versions of Outlook

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A file with the XNK file extension is an Exchange Shortcut file. It's used to quickly open a specific folder or other item in Microsoft Outlook.

XNK files are created by dragging the object directly out of Outlook and placing it on the desktop. Instead of moving the item out of Outlook and onto the desktop, a reference, or shortcut, is built so that you can quickly access that same thing again through the XNK file.

Note: The XNK file extension closely resembles XNB, but the two formats don't actually have anything in common.

How To Open an XNK File

Since XNK files are just shortcuts for opening items in Microsoft Outlook, double-clicking on one will do just that... assuming you have Microsoft Outlook installed, of course.

Important: For security reasons, Microsoft removed XNK support beginning in Microsoft Outlook 2007. If you have that version of Outlook, or later, you'll have to make manual changes to enable this feature. See Microsoft's instructions at Microsoft Support and Office TechCenter for more information on this.

Normally, if you have trouble opening an XNK file in Outlook 2007 or newer, you'll see an error that says "Cannot open file," or “Cannot start Microsoft Office Outlook. The command line argument is not valid. Verify the switch you are using.”.

If Microsoft's solutions didn't work, you can try making some specific changes in the Windows Registry, outlined in this guide at MSOutlook.info.

Tip: You need to know whether you're running a 32-bit or 64-bit version of Windows before you can use that registry tweak. See Am I Running a 32-bit or 64-bit Version of Windows? for help figuring this out if you're not sure.

While I don't think it's very likely, if some other program tries to open an XNK file (not Outlook), see my How To Change the Default Program for a Specific File Extension tutorial for instructions on changing what program is linked to that extension, which should fix that problem.

How To Convert an XNK File

With most file formats, a free file converter can be used to save it to some other format. This is useful if you want to use the file in another program that doesn't support the original file type.

However, this isn't something that can be done with XNK files since they're just shortcut files that point to something else at another location. There is no "convertible" data contained in the XNK file that a conversion tool could use to make the file compatible with any other program but Outlook.

Other Shortcuts Used in Windows

XNK files are shortcuts used explicitly for the Microsoft Outlook program while a similar file type, LNK (Windows File Shortcut), is a shortcut used to open folders, programs, and other files on a hard drive, flash drive, etc.

For example, an LNK file on the desktop can point directly to the Pictures folder so you can quickly open that folder to see all your pictures, without having to go through several steps just to find the folder. Programs you install to your computer often ask you if they can create a shortcut on the desktop so you can quickly open the program from the desktop instead of having to sift through dozens of folders to find the right application file that starts the program.

So while XNK files are shortcuts used to open folders and files inside MS Outlook, LNK files are used throughout the rest of Windows to open folders and files that exist elsewhere.

A mapped drive is another type of shortcut but doesn't have its own file extension - it's just a virtual hard drive that refers to folders located on other computers within a network. Similar to the two shortcuts I just mentioned, mapped drives provide a quick way to open folders on shared network drives.