Single click to return to currently open programs in start bar

Solution 1:

Yes, this is very easy

You simply hold control when you click on the group of icons on the task bar. It will open the last active window within that group!

Source

Solution 2:

I don't think you can achieve described behavior but you can prevent taskbar icon grouping if it helps. You will have a separate tab for each open window/document.

To change taskbar icon grouping settings:

1. Right click on an empty area of the taskbar, and click/tap on Properties
2. Click on the drop down arrow menu to the right of Taskbar buttons
3. Select one of following options:
   • Always combine, hide labels
   • Combine when taskbar is full
   • Neve combine ( <-- I assume this is the one you need )
4. Click "OK" to apply changes

for more details see this link

Solution 3:

Here's a registry hack that allows you to do just that. Instructions from link below:

Open up regedit.exe through the start menu search or run box, and then head down to the following registry key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced

Once you’re there, create a new 32-bit DWORD value on the right hand side, give it the name LastActiveClick, and set the value to 1.

Once you are done, you’ll have to log off and back on, or you can kill Explorer.exe through Task Manager and re-open it and that's it.

Or you could just download the registry hack and double-click it.

Solution 4:

7+ Taskbar Tweaker lets you patch Windows on the fly to always split grouped taskbar icons. You'll be able to switch directly to the window you want. That's not exactly what you wanted, but it's close (and even better, in my opinion).

Why is it better than modifying Registry? Because it's not applying any changes permanently. You'll be able to safely disable it at any time if something goes wrong.