The first rule of opening files is that you must always open the file before using it and close it when the program is finished. This ensures that your data will be saved to disk and not lost if another program opens or crashes. You should also make sure you are opening a file with an appropriate application.
For example, you can’t use Microsoft Word to open a video! If you try, the program will open a blank document and tell you to use an app that can read video files.
Rule two is that when opening any file for editing, make sure it’s in plain text format. If not, then WordPad or another text editor should be used instead of Microsoft Word because formatting information may get lost during conversion into their proprietary formats.
This also includes images that need to have bitmaps saved as BMPs without compression (or PNG) before they are opened by Microsoft Paint because JPEG and GIF create compressed image data which changes the quality of pictures once edited. When working with audio files like MP-files or WMA-files using Windows Media Player 12 on Windows Vista SPN/Windows XP Professional Service.