Often many users see the message "Windows cannot open file, needs to know which program created it" when trying to open an e-mail attachment. You can also get the message... "this file does not have a program associated with it for performing this action create program in control panel ...options"... what do does on look for? As well as mail attachments giving problems, it is possible that you have un-installed a trial version and now when double-clicking on a file you obtain the same message. So do you solve problems such as these?
Both error messages are because someone has sent you a type of file that your software does not recognise. To find out what program is needed you must look at the file extension, which are the last three characters of the file name after the dot.
Most likely this will not be shown in the default Windows installation so in order to see that extension type in Windows Explorer, you must click on Tools, Folder options and remove the tick from "Hide extensions for known file types"
The actual association is performed from Windows and the actual wording on the dialogues boxes will vary a bit depending on version of Windows. So to finally associate or to re-associate a file type, perform the following steps:
1. Highlight the wanted file with a mouse left click
2. Right click on the selected file
3. Select Open With then select Choose a Program
4. Select the required program from the list and check the "Always open with this program"
To identify what program is associated with what file extension, you should visit one of the many Internet sites providing this information. One such site is FILExt.
George Skarbek will be familiar to many computer users as the writer of a popular Q and A column, which has appeared in major newspapers every week from 1996 to 2009. His latest, "Computer Guide", compiles the answers to the most common IT questions. In addition, his book offers over 80 quick and easy hints and tips that are guaranteed to save you time and boost your productivity. Read a sample chapter at Computer Guide