Windows Vista users have been complaining about the thumbnail previews not displaying correctly in the taskbar. Microsoft has released a workaround that will fix the issue. ..
The taskbar previews are actually part of the explorer.exe process, even if they access the DWM service to get the thumbnails.
My first test was to restart DWM, which didn’t seem to do anything. Next, I opened up Task Manager and hit End Process on the explorer.exe process.
Now hit File \ Open on the Task Manager window, and then type in explorer into the Open box.
Your taskbar previews should be back to normal, although you are probably slightly irritated that this was required. If you really wanted to get slick, you can create a script that automates killing and restarting explorer.exe. After a few more times of encountering this, I’m going to do it myself.
