DOS File Extension

What is DOS file?

Files with .DOS extension were used on Microsoft operating systems in the 1990s- MS Windows 95 and MS DOS 7. DOS files were created on the disk when two operating system were installed on the same computer - MS-DOS and then Windows 95. In order to have the option to run either system, dualbooting WIN95/ DOS 7 System was required. To prevent mixups, DOS system files such as config.sys or autoexec.bat have their extensions changed to config.DOS and autoexec.DOS, respectively.

This usage of DOS extension is no longer common. Adding DOS extension to files did not change their contents. MS-DOS and early MS Windows systems are considered legacy software and are no longer developed or maintained, similar case with their system files.

Programs which support DOS file extension

Files with DOS suffix can be copied to any mobile device or system platform, but it may not be possible to open them properly on target system.

Updated: 04/16/2023

How to open file with DOS extension?

There can be multiple causes why you have problems with opening DOS files on given system. Fortunately, most common problems with DOS files can be solved without in-depth IT knowledge, and most importantly, in a matter of minutes. The following is a list of guidelines that will help you identify and solve file-related problems.

Step 1. Install Microsoft Windows software

Problems with opening and working with DOS files are most probably having to do with no proper software compatible with DOS files being present on your machine. The solution to this problem is very simple. Download Microsoft Windows and install it on your device. The full list of programs grouped by operating systems can be found above. The safest method of downloading Microsoft Windows installed is by going to developer’s website (Microsoft Corporation) and downloading the software using provided links.

Step 2. Check the version of Microsoft Windows and update if needed

If the problems with opening DOS files still occur even after installing Microsoft Windows, it is possible that you have an outdated version of the software. Check the developer’s website whether a newer version of Microsoft Windows is available. Software developers may implement support for more modern file formats in updated versions of their products. This can be one of the causes why DOS files are not compatible with Microsoft Windows. All of the file formats that were handled just fine by the previous versions of given program should be also possible to open using Microsoft Windows.

Step 3. Assign Microsoft Windows to DOS files

After installing Microsoft Windows (the most recent version) make sure that it is set as the default application to open DOS files. The process of associating file formats with default application may differ in details depending on platform, but the basic procedure is very similar.

Change the default application in Windows

• Choose the Open with entry from the file menu accessed by right-mouse clicking on the DOS file
• Next, select the Choose another app option and then using More apps open the list of available applications
• To finalize the process, select Look for another app on this PC entry and using the file explorer select the Microsoft Windows installation folder. Confirm by checking Always use this app to open DOS files box and clicking OK button.

Change the default application in Mac OS

• By clicking right mouse button on the selected DOS file open the file menu and choose Information
• Proceed to the Open with section. If its closed, click the title to access available options
• Select Microsoft Windows and click Change for all...
• Finally, a This change will be applied to all files with DOS extension message should pop-up. Click Continue button in order to confirm your choice.

Step 4. Check the DOS for errors

Should the problem still occur after following steps 1-3, check if the DOS file is valid. Problems with opening the file may arise due to various reasons.

1. Verify that the DOS in question is not infected with a computer virus

If the DOS is indeed infected, it is possible that the malware is blocking it from opening. Immediately scan the file using an antivirus tool or scan the whole system to ensure the whole system is safe. DOS file is infected with malware? Follow the steps suggested by your antivirus software.

2. Check whether the file is corrupted or damaged

If you obtained the problematic DOS file from a third party, ask them to supply you with another copy. The file might have been copied erroneously and the data lost integrity, which precludes from accessing the file. When downloading the file with DOS extension from the internet an error may occurred resulting in incomplete file. Try downloading the file again.

3. Verify whether your account has administrative rights

Some files require elevated access rights to open them. Log out of your current account and log in to an account with sufficient access privileges. Then open the WIN95/ DOS 7 System file.

4. Verify that your device fulfills the requirements to be able to open Microsoft Windows

If the system is under havy load, it may not be able to handle the program that you use to open files with DOS extension. In this case close the other applications.

5. Check if you have the latest updates to the operating system and drivers

Up-to-date system and drivers not only makes your computer more secure, but also may solve problems with WIN95/ DOS 7 System file. It may be the case that the DOS files work properly with updated software that addresses some system bugs.

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