You're here because you have a file that has a file extension ending in .umf. Files with the file extension .umf can only be launched by certain applications. It's possible that .umf files are data files rather than documents or media, which means they're not meant to be viewed at all.

A MediaHolder universal media format file is a file used by the MediaHolder software as a means for this application to download multimedia content in different types and formats via file fragments. These MediaHolder Universal media format files are integrated with data compilation and encoding standards proprietary to GetMediaHolder.com, the developer of the MediaHolder application and the UMF file format. These specifications are implemented into these MediaHolder Universal media format files so it can be saved in the UMF format and affixed with the .umf extension. Metadata details associated to multimedia content like ebooks and various digital videos, audio data and other files may also be stored in these MediaHolder Universal media format files, aside from the actual multimedia data. These metadata details can include names of the multimedia content's creators, hyperlink resources that can be used as reference data by MediaHolder users among other files and the types of these files included in the downloads. OnRead.com eBook downloads are implemented with the UMF format. Efficient categorization of multimedia content downloads using the MediaHolder program is possible since this application can use the metadata details stored in these MediaHolder Universal media format files for this purpose.

Launch a .umf file, or any other file on your PC, by double-clicking it. If your file associations are set up correctly, the application that's meant to open your .umf file will open it. It's possible you may need to download or purchase the correct application. It's also possible that you have the correct application on your PC, but .umf files aren't yet associated with it. In this case, when you try to open a .umf file, you can tell Windows which application is the correct one for that file. From then on, opening a  .umf file will open the correct application. Click here to fix .umf file association errors

Be careful not to rename the extension on .umf files, or any other files. This will not change the file type. Only special conversion software can change a file from one file type to another.

A file extension is the set of three or four characters at the end of a filename; in this case, .umf. File extensions tell you what type of file it is, and tell Windows what programs can open it. Windows often associates a default program to each file extension, so that when you double-click the file, the program launches automatically. When that program is no longer on your PC, you can sometimes get an error when you try to open the associated file.