Using Windows

• 1). Navigate to the DAT file you want to open and double-click on the file. The computer will attempt to open the file. You may see a warning prompt letting you know that DAT files are often used by the operating system and not meant to be opened and edited.
  
  
• 2). Click "Open With" and see if the computer can guess which application created the file. If the computer cannot guess what application made the file, you will get another error prompt.
  
  
• 3). Click the "Select Program from a List" if you have an idea of what the file may contain. DAT files can contain graphics, text, music or video. Click "OK."
  
  
• 4). Select a text editor such as NotePad or EditPlus in the Open With dialog box if you do not know what type of file it is. If you think it is a media file, try opening the file with a media player such as the Windows Media Player or VLC Media Player. Once opened, you can modify it in the text editor, or if it is a media file, open the file with a media editing tool.
  
  

Online File Converters

• 1). Navigate to a file conversion website such as Zamzar or CometDocs. Click the "Browse" button. Navigate to the file you want to convert and click "Open."
  
  
• 2). Choose the file type to change the file to and then type in your email address in the "Email" field.
  
  
• 3). Click "Convert" or follow the directions on the site to upload the DAT file and convert it to something you can see and edit. The file conversion website sends you an email link when the file is converted. You will need to download the changed DAT file and open it in the program you specified so you can edit it.