How to fix broken taskbar icons in Windows 7

Based on @dash17291's answer, here is a slightly faster procedure (no reboot) that worked for me:

1. Open Windows Explorer, go to %userprofile%\AppData\Local, delete IconCache.db. (This file is hidden, so it you don't see it, you will need to adjust your Windows Explorer settings to show hidden files.)

2. Open Task Manager, go to Processes tab, highlight explorer.exe, and click End Process. Your desktop will "disappear."

3. Still in Task Manger, select File > New Task (Run...), type explorer.exe, and click OK. Your desktop should reappear, with the previously missing icons.

Rebuild the Icon Cache:

Source: How to Rebuild the Icon Cache in Windows (http://www.sevenforums.com/tutorials/49819-icon-cache-rebuild.html)

To Manually Rebuild the Icon Cache using the Command Prompt

1. Close and save anything that you are working on. This command will kill explorer and restart the computer when completed.

2. Open a command prompt in Windows 7 or Windows 8.

3. In the command prompt, Copy and paste each command line below exactly as is one at a time and press enter after each command.

   WARNING: The last command will restart the computer, so be sure to close and save anything that you are working on first.

   • ie4uinit.exe -ClearIconCache
   • taskkill /IM explorer.exe /F
   • DEL "%localappdata%\IconCache.db" /A
   • shutdown /r /f /t 00

4. The IconCache.db file has now been rebuilt.

5. If the icons are still not displaying properly, then download and merge the ICO option in this tutorial for Windows 7 or Windows 8 to restore the default associations of .ico (icon) files.

You could have unpinned the link in the taskbar and again pinned the application to the taskbar. The icon would have updated itself.

The reason why this happened was icons for applications installed by Windows MSI installers are present with the installer itself. Because of this, when you upgrade the program, the link to the icon breaks. The only way to fix this is either recreate the shortcut/pinned link or update the icon for the shortcut itself by Right Click → Properties → Change Icon...

e.g.: This is a link to the icon for Nokia PC Suite: %SystemRoot%\Installer\{92D1CEBC-7C72-4ECF-BFC6-C131EF3FE6A7}\ARPPRODUCTICON.exe. Note that the icon resides with the installer and not linked to the icon embedded inside the executable.