‘Open With’

My wife’s XP has developed a hiccup. When she wants to play a .flv file – it attempts to open with IE. Solving should be easy using the ‘open with’ function. Yet when I browse for the program to run the .flv file, the ‘open with’ function defaults back to IE.
Oddly, if I choose a different senario, the browse and select function works fine.
Any suggestions on a solution is appreciated.
Ted