File Extension Database

Open UNK File

Files with a UNK extension can have various utilities

Unknown File

UNK could be used to store data from the unknown file which has no file association. It may store the contents of an original file that was not recognized by the program. Usually it is used as a default extension for a corrupted or unknown file found in email attachments or downloads from the web.

The recommendation is that you do not try to open UNK files unless you are sure of their content, as they may contain a virus.

UVProbe

In this case, the files with the UNK extension are a type of UVProbe Data File file developed for the UVProbe software program by Shimadzu Scientific Instruments.

According to the manufacturer's website UVProbe is a multifunctional, easy-to-use software supplied as standard with the Spectrophotometers manufactured by Shimadzu.

Lotus Notes Unknown Attachment File

Lastly, files with UNK extension can be used as Lotus Notes Unknown Attachment. Lotus Notes, today known as HCL Notes, is the common client for accessing the Domino/Notes server and processing e-mail, appointments, contacts and much more.

As an example, a file identified as att1.unk is received by HCL Notes if the original message was transmitted with MIME encoding.

To open UNK files (except for unknown files), you must have one of the following software packages installed:

UVProbe.
HCL Notes.

Open UNK File on Windows

Find a UNK file in question in Windows OS File Explorer and double click on it to launch the corresponding application.
If a UNK file is not opened in an application and you instead get a "Windows can't open a file" error message you should try looking for an application which can open the file in question.
If you know the application which can open UNK file then run it and see if there is a File->Open main menu option in the application.
If you don't know the application which function as UNK file opener then try to search online for "UNK viewer", "application to open UNK file" or "open UNK file" queries in the search engine you like.
Install the application you found and check if it can open UNK file

Open UNK File on Mac OS

Find a UNK file in question in Mac OS Finder and double click on it to launch the corresponding application.
If a UNK file is not opened in a Mac OS application and you instead get a "There is no application set to open the file" error message you can click on "Search App Store" in the error dialog and Mac OS will show you applications compatible with UNK file.
If you know the Mac OS application which can work as UNK file opener you can choose the "Choose Application..." option in the error box to associate the file extension and open UNK file in it.
If you don't know the application which can open UNK file then try to search for "UNK viewer", "application to open UNK file" or "open UNK file" queries in the online search engine you like.
Install the application you found and check if it can open UNK file

Open UNK File on Android

If you downloaded a UNK file on Android device you can open it by following steps below:

In the Android apps list on your Android device find "My Files" or "File manager" app and tap to start it.
Tap on "Downloads" folder inside the app.
You should see your downloaded UNK file in that folder.
Tap on the file. If Android device supports opening the file you downloaded it will open in the corresponding app.
If file does not open you can look for the corresponding app that can open the file by searching Android App Store for the "UNK".
If you cannot open the file with the apps from Android App Store it is possible that the file could only be opened on desktop platforms such as Windows or Mac OS. Try searching for "UNK viewer", "UNK file" online and see if any desktop applications can open it.
It is also possible that the file you downloaded is outdated and is no longer supported.

Open UNK File on iPhone or iPad

To open UNK File on iOS device follow steps below:

Open Files app on your iPhone or iPad device. You can find it by swiping down on the home screen and typing "Files" in the search bar.
Tap on the Downloads folder on the Files app home screen.
You will see all files that you recently downloaded. Tap on the UNK file to view it.
If you have the right app that can open it it will automatically launch and open your file.
If you don't have the app which can open it you need to serch Apple app store for "UNK". This way you can find apps which can open UNK files.
If this doesn't help it is possible that your file could be opened only by the desktop application. To find an app which can open it on desktop look for "UNK viewer" or "UNK file" online in your favorite search engine.

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