The other evening my wife was working on her Windows Vista laptop and encountered an unexpected result. She double-clicked on a .PNG image file and up popped the QuickTime PictureViewer. It displayed the .PNG image perfectly, but she had been expecting the image to be displayed by Windows Photo Gallery, like it always has in the past. Claiming that she didn’t have any idea how such a thing could happen, she asked me to fix it.

I knew right away what had happened. She had recently installed Apple QuickTime to view a movie that a friend had sent to her and must have clicked Yes when the installation procedure prompted her to alter the default programs. As such, QuickTime had taken over all the default graphic file associations. Fortunately, my assumption that it would be an easy fix was indeed true; however, I decided to take the procedure one step further and remove QuickTime from the Open With list by using a quick Registry edit.

In this edition of the Windows Vista Report, I’ll show you how to clear out Vista’s Open With list.

This blog post is also available in PDF format as a TechRepublic download.

Using default programs

As I began my investigation, the first place I looked was in the Default Programs tool. To launch it, just type Default in the Start Search box on the Start menu and press [Enter]. When you launch the Default Programs tool, shown in Figure A, you’ll see that there are four links that allow you to configure how Windows Vista works with programs:

  • Your default programs
  • File type associations
  • AutoPlay settings
  • Computer default programs

Figure A

The Default Programs tool provides you with four different ways to configure your default program options.

For this type of investigation, I selected the file type association option — Associate a File Type or Protocol with a Program. I then scrolled through the list of file types until I located .PNG, as shown in Figure B. As you can see, the .PNG file type is associated with QuickTime PictureViewer.

Figure B

You can see that the .PNG file type is associated with QuickTime PictureViewer.

To reset the file type association back to Windows Photo Gallery, I selected the Change Program button. When I did, the Open With dialog box displayed. At this point, all I had to do was choose the Always Use the Selected Program to Open This Kind of File check box and select Windows Photo Gallery from the list, as shown in Figure C. To complete the operation, I just clicked the OK button.

Figure C

Using the Open With dialog box, you can easily reset the default program that you want to open a particular file type.

Testing the result

I then returned to Windows Explorer, double-clicked a .PNG file, and watched Windows Photo Gallery pop up. However, when I right-clicked on a .PNG file and accessed the Open With submenu, I discovered that PictureViewer was still linked to the .PNG file type even though it wasn’t set as the default program, as shown in Figure D.

Figure D

The QuickTime PictureViewer was still linked to the .PNG file type even though it wasn’t set as the default program any longer.

Now, I am not totally against Apple (even though I’m a PC guy), but I was annoyed that the program had taken over the .PNG file type and so I really wanted to remove all traces of it.

Investigating the Registry

Doing a bit of research on Vista’s Registry structure, I discovered that there are five registry keys that have the potential to control the list of programs that display on the Open With submenu:

  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.xxx\OpenWithList
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.xxx \OpenWithProgIDs
  • HKEY_CLASSES_ROOT\.xxx\ OpenWithList
  • HKEY_CLASSES_ROOT\.xxx\ OpenWithProgIDs
  • HKEY_CLASSES_ROOT\SystemFileAssociations\PType\OpenWithList

Where .xxx is the file extension you are concerned with and PType for a file extension could be audio, image, system, text, or video.

In my case, I found that the link between the QuickTime PictureViewer and the Open With submenu was located in the HKEY_CLASSES_ROOT\.png\ OpenWithProgIDs registry key, as shown in Figure E.

Figure E

The link between the QuickTime PictureViewer and the Open With submenu, was located in the HKEY_CLASSES_ROOT\.png\ OpenWithProgIDs registry key.

After deleting the QuickTime.png Binary Value from the Registry, the QuickTime PictureViewer disappeared from the Open With submenu. (Keep in mind that whenever you delve into the Registry, you are potentially playing with fire. So make sure that you have a recent backup.)

In most cases, you’ll find the item that you want to remove from the Open With submenu in the HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.xxx\OpenWithList registry key as a String Value.

For example, I later went to that registry key to remove Windows Movie Maker from the Open With submenu. In that case, I had to delete the moviemk.exe String Value and the MRUList String Value, shown in Figure F. The reason is that while the moviemk.exe String Value represented the actual application link, the MRUList String Value contains the actual list.

Figure F

In some cases you may have to delete more than one registry key.

What’s your take?

Have you ever discovered that an application has essentially hijacked a file type on your Vista system? Have you ever encountered a program on the Open With submenu that you didn’t want to have there? If so, please take a moment to drop by the Discussion Area and let us hear from you.