When I turned on my computer today, I realized that some of my icons disappeared from my taskbar e.g. Google Talk, Skype etc. When I tried to open Google Talk, the program opened normally, but when I tried to minimize it to my taskbar no Google Talk icon was there. I decided to solve the problem without restarting Windows using the following procedure.
1. Open Windows Task Manager by pressing "Ctlr+Alt+Del" simultaneously.
At the Processes tab, make sure that your program is still running e.g. "googletalk.exe".
2. Select the "explorer.exe" process and end it using the "End process" button at bottom right of Task Manager window.
3. All desktop icons will disappear. Without closing Task Manager, go to "File > New Task" at the left up corner in Task Manager’s window.
5. At the Open command window box, type "explorer.exe" and then choose "OK"
After that, Windows Explorer reloads again and normally you can see your desktop and its icons come back, and you can see again all the running program icons appearing in your taskbar.