Last Updated on May 8, 2026
Understanding File Extensions and Associations
When it comes to opening files on your computer, Windows does this automatically based on the type of file you are trying to open.
If Windows didn’t do this, you would have to manually choose an app to open a file every single time.
You have probably also noticed that your files have icons that match the specific program used to open them.
I am sure you have noticed that at the end of your file names, there is usually a dot or period followed by three or four letters, such as Report.xlsx.
This is what is known as a file extension, and it is used specifically for Windows file associations.
Windows uses these file associations to determine exactly what program to use to open a certain type of file.
For example, Windows will know that resume.docx is to be opened using Microsoft Word since .docx is the standard file extension for Word.
Why You Might Need to Change a File Association
There may come a time when you want to use a different program to open a certain type of file.
You may also download a new type of file that Windows simply doesn’t know how to open yet.
If that is the case, you can easily change the file association to tell Windows which program to use moving forward.
This is not the same as changing the file extension for the file itself, which is something you generally want to avoid doing.
If you just rename the extension, you will most likely not be able to open the file afterwards.
While some formats are safely interchangeable, like renaming a .jpeg to .jpg, changing an extension manually usually makes the file unreadable to the system.
How to Change File Associations Using Open With
The easiest way to accomplish this change is to open File Explorer and browse to the folder where your file is located.
Then you can right-click the file, hover over “Open With,” and then choose a program from the expanded list.
If the program you want to use is not listed there, you can click on “Choose another app” at the bottom of the list instead.
Next, you will be presented with a dedicated Open With dialog box.
ou can then choose another program from the provided list or scroll down to where it says “Choose an app on your PC.”
This allows you to browse your computer’s hard drive for the exact location of that program.
In the modern Windows interface, you will see two options at the bottom: “Just once” and “Always.”
Selecting “Always” sets that application as the brand new default for every single file with that specific extension.
If you do not see the app you want, click “Choose an app on your PC” to manually locate the .exe file in your Program Files folder.
You always want to make sure you choose a program that can actually read and open that specific file type.
If you mess this up or change your mind later, you can come back to any file with that extension, redo the process, and change the associated program again.
Managing Associations via Windows Settings
If you want to see a full list of your file types in one place, you can manage them globally using the modern Windows Settings app.
Step 1: Press the Windows Key + I on your keyboard at the same time to open Settings.
Step 2: Navigate to the Apps section on the left menu and then select Default Apps.
Step 3: Scroll all the way to the bottom of the page and click on the option that says “Choose defaults by file type.”
Step 4: Here you can browse through a giant alphabetical list of every extension and see exactly which program is assigned to it.
Customizing Your Windows Experience
If you are looking for a good app to help you find your files quickly so you can manage their extensions, you may want to check out Listary File Search.
It is a powerful tool that integrates directly into File Explorer to make finding deep-seated files completely instantaneous.
Understanding file associations is the ultimate key to a customized Windows experience.
Whether you prefer a third-party media player over the built-in Windows options or a specialized code editor for text files, knowing how to toggle these associations ensures your computer always uses the tool you prefer.
Just remember: always change the association, never the extension name itself!
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