Fix wrong default program for .DLL files

If you have accidentally set Notepad as the Default Program to open all .dll files, this article will help you to fix that issue. You can change file association by going to Control Panel\Programs\Default Programs and then Clicking on Associate a file type or protocol with a program option. Suppose you want to change file association of a .jpg file from Windows Photo Viewer to Paint. It can be done easily from there. But what if you want to un-associate a file type? Suppose by mistake you have selected .dll to open with notepad by default. Now you want to un-associate .dll file type that means you do not want to select any program to open .dll files by default.

Method 1: For Windows 7 and Vista

To accomplish that you will need to download a small tool. Download from HERE

Now launch Unassociate.exe and select .dll from the list then click on Remove file association (User) option. If the button is dimmed that means there is no user-specific association for .dll file type.

That’s it. The user-specific association for .dll file type is now removed successfully from system registry. Your system will now use the global file association settings, i.e., .dll file type will be un-associated.

Method 2: Fix wrong default program for .DLL files in Windows 8

Above method will not able to solve your problem, if you are using Windows 8. Above mentioned software is not compatible with Windows 8. Follow the steps below :

1. Press Windows Key + R to open “Run” dialog and type “regedit” and hit Enter.

2. In “Registry Editor” dig down to
HKEY_CLASSES_ROOT\.dll\PersistentHandler and double click on (Default) string in right pane. Make sure Value Data is {098f2470-bae0-11cd-b579-08002b30bfeb}

2. Now navigate to

HKEY_CURRENT_USER\Software\
Microsoft\Windows\CurrentVersion\
Explorer\FileExts\.dll

Expand .dll folder and delete UserChoice folder completely.

Now, Reboot your system. That’s it. This method can be followed in other versions of windows as well. Windows 7 and Vista users can follow the previous method also.