Fixing jEdit File Associations

v1.0

"Why does jEdit keep opening files it shouldn't?"

The Problem

You've installed jEdit, the open source extendable programmer's editor, and now when you open files that used to work jEdit opens. Everything from .avi, to .mov, to .jpg files. Worse yet, you've checked your file associations with Tools / Folder Options... / File Types, and they seem to be correct. Even FTYPE and ASSOC from the command line don't provide a clue.

The only thing that does seem to work is renaming the extension to uppercase.

Despite a careful install, jEdit is agressively trying to open everything which doesn't have an explicit case-sensitive match for the file extension when you double click it.

The Solution

What you've got is a registry problem, inflicted by jEdit installation program for Windows. Note that the problem here is not jEdit, which is simply a Java JAR file. Don't blame the application, blame the installer.

Anytime you mess with the registry, it's a good idea to make a backup first.

Consider making a System Restore Point; locate the program called rstrui.exe and run it; it's usually under C:\WINDOWS\system32\restore.

Do Start / Run... / regedit and open your registry.

Locate this entry:

My Computer HKEY_CLASSES_ROOT * Open with jEdit

Right click it and select Delete, confirm with Yes to delete this key and all of its subkeys.

Close the registry editor.

The fix takes place immediately.