How can I change the default program associated with a specific file extension?

Are you downcast because every time you click on an Office document Adobe Acrobat chronically attempts to open it?  Or consider the unforgivable contumely of Windows when it refuses to open JPEG’s with Photoshop.

Fortunately, this is actually a generic problem with an easy solution.

Thanks to file associations, programs such as Winamp will always open music files ending in .MP3.  But let’s say for some inane reason you want .MP3s to open iTunes.  How would you tell Windows to open MP3s with iTunes now?

In this article, I’m going to show you how to change the default program that opens specific file extensions.  Once you see how easy this is you’ll never worry if it happens again and you’ll have a cool tip to entertain geeks at the next Star Wars convention.

Fixing Fickle File Associations

Okay, try saying that title 10 times fast… I digress.

Anyway, the easiest thing here is to simply find to find the file that needs to change associations and right click it and choose Open With… then pick Choose default program… 

Grrr… I’m tired of Notepad trying to open my JPEGs…

Windows 7 Open With

Now pick the desired program from the list.  If you don’t see it there, click Browse to find the executable.  In my case, I’m going to use the basic Windows Photo Viewer.

Make sure Always use the selected program to open this kind of file is checked then click OK and you’re done.

Open With

Get the gamut…

If you need to see the full spectrum of file associations click Start and type:

set your default programs

Windows 7 set your default program

You can peruse your programs in the left pane and then either make it the default for all relevant files or hand pick specific file types by clicking Choose defaults for this program in the right pane.

But if you want more control (or want to get your fingers dirty inside the digital guts of your computer) check out the registry.

Ratify the registry…

Let’s face it:  I’m a geek.  You’re a geek.  Everyone’s a geek geek.

We like fiddling with stuff so that’s why I need to show you how to manually delete default program associations using the rarefied Registry Editor…

Click Start and type


When Reggie (my nick name for Regedit) whirls onto the screen, navigate to the registry key here:


and here


Windows 7 Registry Editor

Make sure you click File then Export… to save a backup of your registry first then zap the sub keys under \FileExts that are the same name of the extensions you want to disassociate.

Now you can either reboot the computer or use the explorer.exe trick to restart the shell without actually rebooting.

That’s all folks.  If this helped you (or pissed you off) let me know in the comments!


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Posted in How To, Windows 7
  • Howard Schlossberg

    Here’s where I keep failing with this, and your screenshot confirms for me that the problem isn’t just mine. When I open the “set your default programs” window, Firefox is the first program listed for me. I have plenty of programs that come before Firefox alphabetically, yet they don’t display. Same seems to be true in your screenshot, where you are scrolled to the top yet the first item shown is Foobar. What is the fix for THAT?!?!