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

Files in the DAT format are appended with the .dat extension and can be authored, opened and edited using the associated Microsoft Windows application or the Mac software which was used to create the DAT file. These DAT files are generic data files that can also be opened using any Microsoft Windows text editing application or any text editor developed for Mac platforms. These DAT files can be encoded in plain text format, while some DAT files are implemented with binary encoding specifications. Users of Microsoft Windows-based systems can use the Microsoft Notepad text editor to open a DAT file, while Mac users can use any Apple text editor to do this, though it is advisable to determine the specific software that was developed to create or open and view the content stored in a DAT file. For instance, some VCDs contain DAT files that can be opened and viewed using Microsoft Windows Media Player, and when you open these DAT files with Microsoft Notepad, binary codes are displayed and not the video content stored in the DAT file.

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

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