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

The "SGM" in the .sgm file extension stands for Standard Generalized Markup Language. This is coding language technology for generating digital documents, and this is commonly implemented into applications as a digital information sharing standard. Files in the SGM format contain text data with some layout and formatting attributes entered by the creator of the .sgm file. Among these pieces of text are custom tags also entered by the creator of the .sgm file, and these tags provide brief descriptions of how the content stored in the SGM file was outlined or structured by the file creator, as well as a description about the general overview of the content in the SGM file. Usually, these SGM files use Document Type Definition documents as reference data, and these Document Type Definition documents are files appended with the .dtd extension. Objects that can be embedded into these SGM files as well as the custom tags, pieces of text, formatting attributes and text layout characteristics allowed to be entered by the creators of the SGM files are defined by the associated DTD files. These SGM files can also be saved in the SGML format. Some Microsoft Windows applications that can be used to create, open or view and edit/modify SGM files include the Adobe FrameMaker 10 program and the Corel WordPerfect Office X6 software.

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

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