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

The MWD file extension is used for a MarinerWrite Document created by Mariner Software. Mariner write is a word processor used for Mac OS X and includes Mariner Calc, a spreadsheet application used for analysis and organization of information in a tabular (table data). Bothe Mariner Write and Mariner Calc were released to the public in 1990 and have been identified as one out of five top Microsoft Office options for users of Apple Macintosh Computers. The creators of Mariner Write (Mariner Software) is currently located in Minneapolis, Minnesota and has been since then an established name in the development and design of computer software. The company is at present involved in the creation of new software products namely Mariner Paperless digital document management software, Montage screen writing software, Contour screenplay development software, Winjournal desktop blogging software and MacJournal. Mariner software focuses on productivity with support on personal and professional software. It also aims to develop software for creative and writing markets.

Launch a .mwd 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 .mwd 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 .mwd files aren't yet associated with it. In this case, when you try to open a .mwd file, you can tell Windows which application is the correct one for that file. From then on, opening a  .mwd file will open the correct application. Click here to fix .mwd file association errors

Be careful not to rename the extension on .mwd 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, .mwd. 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.