Windows 7′s Aero Peek feature is what allows for the live thumbnail view as you mouse-over the running applications within your task bar. It makes for a beautiful presentation of what is currently running and can aide in finding a particular instance of an application – but it also can bring about some frustrations.

Think about it this way – each instance of an application is condensed within one icon on your task bar. If you have 6 Word documents open, mousing over the familiar Word icon would then show 6 thumbnails, one for each opened document. Given the power of even a three year old PC it’s not uncommon to have multiple things running even though you may only be using two particular applications on the day at hand. If I’m writing a research paper and am referencing Wikipedia I’m constantly flipping back and forth between my browser and Word. This is where Aero Peek can transition from a nice UI feature to a bane to your existence. Switching to your document requires two clicks, one on the Word icon and then a second on the appropriate thumbnail.

Keyboard junkies are quick to point out that if you instead hold down CTRL while clicking on a task bar application you will switch automatically to the last referenced instance of that application – similar to Windows XP. While it solves the immediate annoyance it’s not something you really want to have to do every time right?

The behavior can be changed using the Windows registry.

Launch regedit from the Start->Search box.

In the left hand navigation panel traverse to the location HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced

Create a new 32 bit DWORD value by right-clicking in the right hand panel. Name the DWORD LastActiveClick and give it a value of 1.

You will need to restart Windows Explorer to apply the change; the easiest way is to just reboot the computer. The result when clicking on the task bar icons is as if you had CTRL held down as above. If you hover over the icon the application instance icons will appear just as before. It’s basically the best of both worlds!