Opening UNKNOWN files
Did your computer fail to open an UNKNOWN file? We explain what UNKNOWN files are and recommend software that we know can open or convert your UNKNOWN files.
What is an UNKNOWN file?
The .unknown file extension is often used by some data recovery tools for flagging files that have not been completely recovered. This UNKNOWN file format may also be used by a few data recovery tools for flagging files that have been corrupted beyond repair. These .unknown files may not work properly, even when opened using an application that has support for its original file format.
The UNKNOWN file format may also be used by certain download management programs and P2P (peer to peer) file sharing tools. Files that have not been completely downloaded may be appended by these applications with the .unknown file extension. These UNKNOWN files may be converted by these download management and P2P applications into its original format as soon as the download has been successfully completed.
It's best to leave these .unknown files alone, especially if the file is sent via email from an unknown source. Certain Web browsers may also flag incomplete download items as UNKNOWN files during the download process.
Software that will open, convert or fix UNKNOWN files
Try a universal file viewer
In addition to the products listed above, I would suggest that you try a universal file viewer like Free File Viewer. It can open over 200 different types of files - and very likely yours too! Download Free File Viewer.