I'm at a loss because Windows should automatically hand the folder location over to Windows Explorer to display.

Is there a pattern to it or does this occurs for all folders on your system?

If you double-click the download to launch it, does that work?

By the way, did this problem start when you installed Firefox Beta (future Firefox 27), or did it start for you in Firefox 26?

I get the error when I click the folder icon (or if I right click on the folder icon) on a downloaded file in the Firefox Downloads window to "Open Containing Folder". I'm not sure when it started, certainly within the last few days so it may have started with FF27b2. I've been trying some Explorer alternatives (FreeCommander XE and others), so possibly one of these changed a registry key that I can't find. I totally uninstalled and reinstalled FF and tried Safe Mode all with the same result which makes me think it's a Windows issue.

Just tested FF27b2 on another computer with same Win7 64-bit and it's fine, so pretty sure it's a Windows registry problem.

I created a new user account in Windows. Same problem with the different user.

I think you have a problem with your Windows Registry and I may have a solution that you could try...

Please set a System Restore Point before attempting this

This isn't that hard as long as you follow the instructions:

• Open Run by hitting Windows key + R or by the Start Menu
• Search "regedit" and hit enter
• Once in the Registry Editor,navigate to the following key, HKEY_CLASSES_ROOT \ exefile \ shell \ open \ command
• Double-click the (Default) value in the right hand pane and delete the current value data, and then type: "%1" %* exactly as shown including the quotes and asterisk.
• Navigate to HKEY_CLASSES_ROOT\.exe
• In the right-hand pane, set the value data for (default) to exefile
• Exit Registry Editor

I would love to know if this does or does not work for you so please reply back after performing these steps and tell me if it worked for you.

No, still doesn't work. I'm sure you are on the right track though -- that it's a Windows problem not a Firefox problem -- because I have the same issue with another application that has the same functionality "open destination folder". There is no error, it just doesn't do anything. Fortunately I have another computer with the same OS and Firefox and "Open Containing Folder" is working, so I can compare registry values. I'm just not sure where to look, there are a lot of Registry keys!

Try to ask advice at a Windows oriented forum.

• http://www.bleepingcomputer.com/forums/
• http://windowssecrets.com/forums/

OK, kinda figured it out. I had run an Explorer replacement called Q-Dir as a Portable app. One option it has is to use Q-Dir as the default browser. It DID warn me that the change would be made to the Registry. I had since removed the program (settled on FreeCommander XE) but I hadn't "unset" Q-Dir as the default browser. With the program gone, I got the error. I had searched the Registry for "Q-Dir" previously, but didn't find any reference to it, so I don't get that... Anyway, Open Containing Folder works, and the "open destination folder" in qBittorrent works as well.