How do I dissociate a program from a file type?

Solution 1:

In a discussion I found, a Microsoft MVP recommended the use of this program, "unassoc.exe", perfect for your needs.

unassoc is a small portable executable, whose only UI elements include a list of all file types with associations on your computer, the ability to select one or more extensions, and the ability to delete the file type associated with that extension.

Also, if you're simply worried about the overhead of having multiple file extensions registered to a program you don't have installed anymore, the registry cleaner bundled with CCleaner can automate this process for you. It can scan for unused file extensions, and delete the relevant registry entries.

Solution 2:

In Windows Vista you click the Start button and select "Default Programs". There are several options -- you probably want "Associate a file type or protocol with a program".

Solution 3:

Use regedit to remove the keys associated with the file extension. Then restart explorer.

1. Open regedit.

   • Win+R.
   • type regedit.
   • Enter.

2. Delete .ext keys / values from the registry.

   • Edit -> Find.
   • Enter extension name with preceding dot (ex- .txt).
   • Delete found keys / values.
   • Use F3 to goto next search result.
   • Delete all such keys / values until end of search.

3. Restart explorer.

   • Open Task Manager.
   • Find Windows Explorer.
   • Right Click -> End Task.
   • Repeat the same for remaining Windows Explorer.
   • Win+R -> type explorer -> Enter

This should unassociate the file type.