UNKNOWN File Extension

UNKNOWN file icon
Unknown Format Type

What is UNKNOWN file?

Files with UNKNOWN extension are system files that do not have an valid file extension. This type of extension is usually added to files unrelated to any available software. Such file is not a stand-alone file, only a placeholder for proper file. A situation where a UNKNOWN extension was deliberately added to valid file as a privacy protection measure is also a possibility.

Opening UNKNOWN file

UNKNOWN file can be opened given it was saved in plain text format. This way users can deduce from the contents the correct file extension and manually change it. However, if the UNKNOWN file is saved in a binary format, text editor may not display file contents properly. UNKNOWN files will remain is such form until a software that recognizes this format is installed on the system.

Programs which support UNKNOWN file extension

Below is a table that list programs that support UNKNOWN files. UNKNOWN files can be encountered on all system platforms, including mobile, yet there is no guarantee each will properly support such files.

Programs that support UNKNOWN file

Updated: 01/05/2020

How to open file with UNKNOWN extension?

There can be multiple causes why you have problems with opening UNKNOWN files on given system. What is important, all common issues related to files with UNKNOWN extension can be resolved by the users themselves. The process is quick and doesn’t involve an IT expert. We have prepared a listing of which will help you resolve your problems with UNKNOWN files.

Step 1. Install Original program software

Problems with opening and working with UNKNOWN files are most probably having to do with no proper software compatible with UNKNOWN files being present on your machine. To address this issue, go to the Original program developer website, download the tool, and install it. It is that easy The full list of programs grouped by operating systems can be found above. If you want to download Original program installer in the most secured manner, we suggest you visit website and download from their official repositories.

Step 2. Update Original program to the latest version

You still cannot access UNKNOWN files although Original program is installed on your system? Make sure that the software is up to date. Software developers may implement support for more modern file formats in updated versions of their products. If you have an older version of Original program installed, it may not support UNKNOWN format. The most recent version of Original program is backward compatible and can handle file formats supported by older versions of the software.

Step 3. Set the default application to open UNKNOWN files to Original program

If you have the latest version of Original program installed and the problem persists, select it as the default program to be used to manage UNKNOWN on your device. The process of associating file formats with default application may differ in details depending on platform, but the basic procedure is very similar.

The procedure to change the default program in Windows

  • Clicking the UNKNOWN with right mouse button will bring a menu from which you should select the Open with option
  • Select Choose another app → More apps
  • Finally select Look for another app on this PC, point to the folder where Original program is installed, check the Always use this app to open UNKNOWN files box and conform your selection by clicking OK button

The procedure to change the default program in Mac OS

  • Right-click the UNKNOWN file and select Information
  • Find the Open with option – click the title if its hidden
  • From the list choose the appropriate program and confirm by clicking Change for all....
  • If you followed the previous steps a message should appear: This change will be applied to all files with UNKNOWN extension. Next, click the Continue button to finalize the process.

Step 4. Verify that the UNKNOWN is not faulty

You closely followed the steps listed in points 1-3, but the problem is still present? You should check whether the file is a proper UNKNOWN file. Being unable to access the file can be related to various issues.

1. The UNKNOWN may be infected with malware – make sure to scan it with an antivirus tool.

If the file is infected, the malware that resides in the UNKNOWN file hinders attempts to open it. Scan the UNKNOWN file as well as your computer for malware or viruses. If the scanner detected that the UNKNOWN file is unsafe, proceed as instructed by the antivirus program to neutralize the threat.

2. Verify that the UNKNOWN file’s structure is intact

If the UNKNOWN file was sent to you by someone else, ask this person to resend the file to you. It is possible that the file has not been properly copied to a data storage and is incomplete and therefore cannot be opened. It could happen the the download process of file with UNKNOWN extension was interrupted and the file data is defective. Download the file again from the same source.

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 Unknown Format Type file.

4. Make sure that the system has sufficient resources to run Original program

If the systems has insufficient resources to open UNKNOWN files, try closing all currently running applications and try again.

5. Ensure that you have the latest drivers and system updates and patches installed

Regularly updated system, drivers, and programs keep your computer secure. This may also prevent problems with Unknown Format Type files. It may be the case that the UNKNOWN files work properly with updated software that addresses some system bugs.

Do you want to help?

If you have additional information about the UNKNOWN file, we will be grateful if you share it with our users. To do this, use the form here and send us your information on UNKNOWN file.

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