Win 7 task bar buttons - combine for some applications or not other applications

Question

Is it possible to let task buttons of some applications never combine and others always combine?

For example, never combine for Outlook, Excel and Visual studio and always combine for others.

Answer 1

I haven't found a way yet to automate this, but it can be done manually. Windows 7 and later use Application User Model IDs (AppUserModelIDs) to determine which windows to group/combine and which ones to treat separately. It is possible to change the AppUserModelID (AppID for short) of a running process, and a handy utility that can do this and much more besides is 7+ Taskbar Tweaker (can be installed in portable mode).

1. Say your taskbar looks like this:

   

   As you can see, Windows Explorer buttons are grouped/combined by default since they share the same AppID.

2. Now start 7+ Taskbar Tweaker and click on the Taskbar Inspector button to launch it:

   

3. As you can see in the screenshot below, the two Explorer windows are grouped under explorer.exe since they share a common AppID:

   

4. Right-click any one of the Explorer entries, go to Change Application ID and set it to the random value displayed (see screenshot above).

5. Voilà, you'll see that the Explorer buttons on the taskbar immediately get dissociated:

   

   If you have Aero Peek turned on, you can confirm by hovering over either Explorer taskbar button. You will now see that neither preview displays the other window any more.

You can use the same trick to arbitrarily group/combine any set of application windows. For example, you can group/combine an Explorer window with an Outlook window, if you so wish.

Unfortunately, there is no way to save state yet, so as I said above doing it manually is possible, but a pain if it has to be done repeatedly. I guess this should be a cue to some enterprising programmer to build such an automation utility immediately! :)