Which program to open this file

[#1]

I Guess  most users will know how to find the appropriate file to open a program but for anyone who gets the message.......Windows needs to know which program to open this file and is unsure the following might be of help,
http://www.openwith.org/download

[#2]

Suitable for people who have to be told which is the correct end of a spade to hold.

[#3]

can be a problem when you get an AVI file though