So you just received an email with an attachment that someone sent you, but the extension on the file is .DAT. What exactly is a .DAT file and how to you open .DAT files? Those are two questions I’m going to try to answer as this is an issue that I’ve seen many times in my IT career!

The first thing to understand about .DAT files is that it indicates a file that has arbitrary data. That means it’s not associated with any one particular program or application. When you see a file with a .XLS extension, you know it’s referring to an Excel file, and so on. But with .DAT files, you have to figure out how to open it yourself and it may not be the same program each time.

The best way to open a .DAT file is to use the program that created it. However, if you’re not sure, you can always try Notepad. Now when you open it in Notepad, you may be able to recognize some of the data, but the rest will most likely be junk spewed out by the program that created it.

You’ll normally only see this file format when receiving emails with attachments. Most common programs today do not generate .DAT files and only computer programmers use these files on any kind of regular basis.

So your first step would be to ask the person who sent you the email if they know which program was used to create the file. Now if they tell you that they actually sent a picture or a document and they are not sure why it’s a .DAT file, it could be that the file extension was changed in the process of having the email routed to you.

For some strange reason, some email programs automatically change the file extension on email attachments to .DAT. So if the person sent you a picture and now it’s a .DAT file, you first need to save it to your computer and then change the file extension to JPG or GIF or PNG or whatever you think it’s supposed to be. If they sent you a Word document, change it to .DOC, etc.

You can change the file extension on a file by first going to My Computer, clicking on Tools and then Folder Options.

Next click on the View tab and then scroll down to the option “Hide extensions for known file types” and UNCHECK it. In this way, we’ll now be able to see the file extension and change it to something else.

Now simply right-click on the .DAT file and change the file extension after the dot to the desired file format.

You should also see the icon representing the file change to the appropriate program use to open that file type, i.e. Excel in the above picture.

So what do you do if you’re not sure which program it came from or what the original file extension was supposed to be? You can also try right-clicking on the file and then choosing Open With and try different programs. For example, I changed one of my Excel files to a .DAT extension and then right-clicked on it to open it with Excel and it worked!

Now I just chose Microsoft Excel from the list and Excel was able to read the file since the data was written by Excel, it just had a wrong file extension.

You can also try other programs like Windows Media Player since it will open it if it happens to be a video, MP3, or similar media format. So hopefully you are now able to open your mysterious .DAT file using one of the above mentioned methods! If not, post a comment and I will try to help! Enjoy!

If you've ever been unable to delete a file in Windows, and can't figure out what program's using it, Unlocker is the solution. Have you ever seen these Windows error messages?
*Cannot delete folder: It is being used by another person or program
*Cannot delete file: Access is denied
*There has been a sharing violation.
*The source or destination file may be in use.
*The file is in use by another program or user.
*Make sure the disk is not full or write-protected and that the file is not currently in use.

Unlocker can help! Simply right-click the folder or file and select Unlocker. If the folder or file is locked, a window listing of lockers will appear. Simply click Unlock All and you are done!

Please perform these instructions:
1. Download this free utility:
http://download.cnet.com/3001-2248_4-10493998.html?spi=04b0020b26165a844d759ffe91d1bd24

2. Run the downloaded file "unlocker1.8.8.exe" and install the software.

3. Navigate your way to a blocked file, right-click on it and select "Unlocker".


4. In the window that has appeared select "Delete" option and press OK button.
5. Reboot your system if your asked.

Almost everyone has ever accidentally deleted files. And sometimes these files can be very important. So if in order not to loose these files completely and recover the successfully you should keep in mind following rule: "Don't write anything to the disk with deleted files". Almost any file can be recovered if nothing was written over it. So to recover files follow this simple instruction:

1. Install PC Inspector File Recovery (you can use any other recovery utility).

2. Open it and follow wizard steps.

3. Choose files and recover them.

The important feature of MS Office is Autosaving feature.

In the case of application crash, unexpected PC shutdown or reboot the data which was not saved will be lost. To prevent this MS office provide Autosaving feature. It is enabled by default and set to save document every 10 minutes.

In order to configure Autosaving do the following:

1. Open your Microsoft (Word, Excel, PPoint, Access Etc.) document.

2. In Office 2007, e.g. Word, Click on the Office Button in the top left hand corner of your document.

3. Click on the Word Options button at the bottom of the Drop-Down Menu.

4. In the left pane, Click on the Save option and under the “Save Documents” heading ensure that the “Save AutoRecovery Information every” Checkbox has a tick in it.

Set the necessary time period and click Ok.

In MS Office XP or MS Office 2003, (Word, Excel, PPoint, Access Etc.), Go to “Tools” choose “Options” from the menu and in the dialog box, Click on the “Save” tab and you will see the same feature similar to Office 2007, make your changes and click ok to accept the changes and you are done.

You can show hidden files or folders in the Windows Explorer, by adjusting a small option. Doing so will display the hidden files in the explorer, just like normal files. The "how to"-description for Windows XP and Vista can be found below.

To see hidden files in Windows NT, 2000 or XP:

1. On the Tools menu in Windows Explorer, click Folder Options (To access Windows Explorer, click Start, point to All Programs, and then click Windows Explorer.).

2. Click the View tab.

3. Under Hidden files and folders, click Show hidden files and folders (additionally if you need access to system files clear check box "hide protected operating system files").

4. Click on OK.

To see hidden files in Windows Vista:

1. Open the Windows Explorer, via "Start" > "This Computer" or via the shortcut [Windows-key] + E. Once started, you can go to "Organize" and choose "Folder and Search Options".

2. Once this is opened, continue to the "View"-tab and select "Show hidden files and folders". Confirm this by clicking "Apply" and exit by using the "OK" button.

Hidden files and folders will now be displayed by default.