cannot open file .out

[taifanh]

when i open file .out, codeblocks saids that "codeblocks does not yet know how to open this kind of file. please select what you want to do with it: 1. select an external program to open it; 2. open it with the associated application; 3. open it inside the codeblocks editor". then i choose 1 and after that, i can't open file .out by click double in file. this problem exist with another file. how can i select set up again or how to fix it.