Identification

• A DAT file simply stands for data file and is not an acronym. DAT file contains data in ASCII (American Standard Code for Information Interchange) format and usually comes in comma delimited. Any text editor such as Microsoft Word, Microsoft Notepad and WordPad, to name a few, can open DAT files. A DAT file commonly uses .dat as a file extension, for example winmail.dat for a form of Windows mail DAT file seen in Microsoft Outlook e-mail attachments.
  
  

Types

• There are three file associations for a DAT file extension. The first is a data file, which is the most commonly encountered among the three file extensions. It is a generic data file whereby a specific application created it and accessed only by that application. Some generic DAT files come in text-based format viewed with a text editor. The second is the winmail.dat, which is not as common as the first one. This file extension usually arrives through the e-mail that utilizes a form of Exchange Server such as MS Outlook. The recipient usually receives this attached to the e-mail if the recipient does not support RTF (rich text format) messages.
  
  If you try to open a winmail.dat, it may show only gibberish information that would be difficult to understand. Oftentimes the recipient would end up contacting the sender to resend the information or send the e-mail in another format, such as Internet mail. Open winmail.dat with Microsoft Outlook, Microsoft Mail for Windows or Winmail Decoder Pro. The third type is the VCD file. This is typically a video stream from a video CD (VCD) disc that contains the actual video saved in MPEG-1 and MPEG-2. It is best not to open VCD files with another application; instead view it using a video player that supports MPEG formats.
  
  

Considerations

• When trying to open a DAT file, check first the file association so that you can use the right programs to open them correctly. Some of the tools to open the generic files are text editors such as Notepad, MS Word, Edit Pad, Microsoft Visual Studio and Corel WordPerfect. First try Notepad, which comes built into the Windows machine, before trying the other applications that may have associated costs.
  
  

Prevention/Solution

• You can prevent sending winmail.dat file in an e-mail by using the plain text or rich text format. Go to the "Tools" menu in Outlook and choose "Options." Click on "Mail Format" tab, select "Plain Text" where it says "Compose in this message format," and then click "OK." Outlook will then send all your messages in plain text, eliminating the winmail.dat.
  
  Another way is to select specific users that always have problems with winmail.dat from your -email. You can disable the formatting in RTF messages by going to the personal address book. Go to "Tools" menu then select "Address Book", select the person's name and then click "SMTP-General tab." Then uncheck the box that says "Always send to this recipient in Microsoft Exchange rich text format." Click "OK" to save the changes.
  
  

Effects

• The common negative effect of DAT files is usually having the need to find the right method to open them. This can add delays to communications and productivity, especially if time is of an essence when trying to open the files into a readable format. At times even the same application that created them would not work, and the reader would end up with gibberish useless information. In businesses that depend on fast communications to their clients and partners is essential, getting winmail.dat extensions would delay communications between the sender and recipient, wasting precious time especially if the sender had already signed off and become unreachable to make the corrections.