I cannot open a 20 file. What should I do? Help!

If given user account does not have necessary permissions to open files with 20 extension, it is highly probable that no program that supports given files is installed on the users’ system. Below is a list of actions user should pursue in order to resolve most common problems.

After the application has been installed, the system should automatically open 20 files with given application. Below is the list of relevant programs along with operating systems they are available for:

It is possible that an application that supports 20 files is not associated with such files. In such case, the program should by manually associated with 20 files (right-click on the file icon → Properties → General Tab → In submenu "Open with" and click on "Change" button. System will display a list of suggested programs that support 20 files. Choose the application by checking the box "Always use the selected application to open this kind of files". System will store this information in its registry and use it to open 20 files with the selected program.