For some strange reason my Advent 5421 running Vista home edition has lost the file types on some of the icons mainly all the microsoft ones and have no idea why?? All of them now show as unreconizable file but some will still open and others like MS word 2007 will not open
I agree with whs. Programs like CCleaner, Adware....... can corrupt file extensions.
Example is in CCleaner you have the option of removing Unused File Extensions. While this is handy, I have found I have to go through and unselect a good many of the File Extensions it selects from programs I actually use every day
Theres no way to set them all back to default but this site does have a registry fix for a good many of the common ones