3 ways to open files with unknown file extensions, in Windows

We all encountered files with uncommon extensions, from time to time. Of course many of us know about .docx files, .pdf files, .mp3 files or .iso files. However, have you heard about the .eps file extension? How about .dng? What do you do if you have to open such files? In this article, we are going to show you how to deal with files with unknown file types and learn which apps or programs you should install to view their content. Let's get started:

First Phase: Meeting the unknown file

As we cannot cover how to open every file extension that was invented in the world of computers, we are going to share a practical example using an unusual file and what we did to understand how to open it and view its content. Let's say that someone emails you a file with the .eps file extension.

An unknown file with the EPS extension, shown in File Explorer

The first instinct is to double-click on the file. Windows has no idea how to open this file type, using its own preinstalled programs. As a consequence, Windows asks you "How do you want to open this type of file?".

Windows 10 asking: How do you want to open this file?

The most important rule when using a PC is: do not panic. There is always a solution and, if you try one of the following methods, you should be able to open the file. You are now entering the second phase.

Second Phase - Research the unknown file type

You can use multiple methods to find how to open the unknown file. Whether it's looking for an app in the Microsoft Store, searching on your favorite search engine, or browsing on various websites, everything you do at this point is called research. It usually takes a matter of minutes:

Method 1. Search the Microsoft Store for an app that can open the unknown file

When Windows asks how you want to open this file, you can click or tap "Look for an app in the Store." The Microsoft Store opens showing all the apps that can open this file. Generally, we do not recommend this method, because the Microsoft Store holds mostly non-desktop apps which cannot open that many files and your results might be disappointing. Thankfully, however, the Microsoft Store also includes a small number of desktop applications, which can be used to open more complex files. Still, there is a small chance that you might find the appropriate app by using this method.

The Microsoft Store share what apps can open the eps file format

Method 2. Search the FILExt database to find out how to open the unknown file

Searching online is always the best method to learn about a new file type, and the best place to do it is the Filext database. It is an impressive database which contains over 50,000 known file extensions.

The FILExt online database

To find the unknown file type, you can either go through the alphabetical lists or use the search. Once you find the file extension that you are interested in, click or tap on it, to see all its details. You should find at least a few programs that can open that type of file, as well as details about its purpose and history.

The details page of a file extension, on the FILExt website

Method 3. Search the internet to find out how to open the unknown file

If you still have not managed to find out how to open the unknown file type, you should also try to look for information about it on a search engine such as Google or Bing. By using a search engine, you should be able to see what type of file your unknown file is, in which situations it is used, and what software can open that unknown file type.

Searching Google for information about an unknown file type

What to do once you find out what app you need to open the unknown file?

Let's continue with our example: based on what Google says, the .eps file format is a graphics file format that is used in Adobe Illustrator. That means that we should install Adobe Illustrator and open the file. The problem is that this app is commercial and we do not own a license for it. So, the next question is: "Do I have to pay for software to open this unknown file?".

The answer is: not necessarily, but in some cases, you may have to. You can always look for free, open-source alternatives to open files, but you might not get all the features found in their paid counterparts.

To find the appropriate app that can open your file, you should look through the search results and spot some app names. For example, if you go to Wikipedia and type in the name of the extension, you might find the information you need right there. Here is an image showing what programs can open the .eps file format.

List of apps that can open EPS files, shown in a Wikipedia article

In our research journey, we decided to open the .eps file with GIMP, an open-source image editing program. What do you know? It worked! :)

An unknown file with the EPS file extension opened in GIMP

NOTE: What if you have the right software for opening your unknown file, but you keep getting errors and you still cannot open it? Do not panic: some apps require codecs to be able to open specific files. If you stumble upon such a situation, try searching the internet for the specific errors that you are getting. If you cannot find anything relevant, the file you are trying to open may be corrupt, or the codecs were not installed correctly.

Bonus Method: Ask!

If searching does not help you, or you just cannot find something that can open your magic unknown file, try asking the person who sent it. You might only need to install one small viewer or do a bit more complicated work as we did above. If you are lucky and your friend is a tech-savvy type, he/she might be able to help you.

Always be cautious

When downloading unknown file types, you must be careful so that you do not get malware on your computer or device. This applies not only to the files you download but also to the viewers and codecs you install to view those files. Research thoroughly, and if you are still not sure, ask a more qualified person for advice. This article is going to help: How to avoid the risks and dangers of downloading free apps and games from the web.

Last but not least, take care that you are using legally obtained software to open the unknown files. If what you need is free or open-source software, there is nothing to worry about, but if you need something more complex, purchase it, do not use pirated apps. It is the best way to protect yourself from malware threats, and you also reward the people who worked hard for that application that you need.

Do you often need to open unknown file types?

If you encounter an unknown file type, it takes only a few minutes of research to discover how to open it. There are some basic methods of finding out what type it is, what programs can open it and what it is used for. After making sure that it is safe and that you can acquire the appropriate software safely, you can go ahead and apply some of the solutions found online. If you have questions, do not hesitate to ask in the comments section below.