To open a document with a different program than the one currently associated with it, right click on the file on the desktop or in Explorer and select Open With. Then, choose the program you want to use. If the program is not in the list, select Choose Program and select one from Other Programs. If the program still cannot be found, you can select Browse and go to the executable file of the program you want to use. However, you have to know the name of the file (.EXE file) and its folder location on the hard disk.
Windows May Ask You
If you open a document that has not been previously associated, you will get a "Windows cannot open this file" message. As above, you can select the program by name or by its executable file if you know it. You can also let Windows use a Web service to find the appropriate program, but chances are it may not find anything. To manually associate a file type with an application, see Win File association