Windows 7 problem changing a particular file association

[sapient]

SOLVED: problem changing a particular file association

Hello!
I have a problem trying to change the program associated with a particular file extension. I was trying out different programs to find out how they could handle that particular file type, setting them as the default program and trying to open the file. But after setting the default to one program in particular, it seemed to "lock" the file type as its own, and the association will not change any more. When I right-click on the file and choose "open with..." then "choose default program", the "always use the selected program..." check box is disabled. This is true only for that particular file extention, all other extensions have this option enabled and the association can be changed. If I open the default programs control panel, and try to choose a different program to be associated with that particular extension, the entry does not change after choosing the program and clicking "OK" - it stays at the previous setting.
Please help.

edit: solved it myself. The was a "user choice" entry in HKLM/software/classes/file extension. I do not know how it got set, but removing it re-enabled the option to choose the default program for that particular extent ion in explorer

 

[stueycaster]

Here's a good site to find out about file associations.

FILExt - The File Extension Source

 

[SteveMann]

Thanks for the Filext tip, but I already know what the extension association is supposed to be, which is all the FileExt site does, plus try to sell me yet another Registry Scanner that I will never buy. The problem I am having is that I cannot select the installed program to run when I double-click on the associated file.

 

[Elmer]

What sort of file is it?