Windows 7 System Tray icons blank or do not refresh

[Alfisti33]

Hello, I have a problem with my Windows 7. some times the tray buttons stuck on, but the program is off or some times stuck like empty squares without an icon.

What is it and what can I do?

I think that is because of an update but i dont know for sure.

[HappyAndyK]

Rebuild the icon cache.

See this for more ideas - Troubleshoot system tray icons.

[Lewis-H]

Step 1: Backup Registry. Go to Start > Run (or Windows-key + R), type in regedit and hit OK. ...
Step 2: Navigate to the key: HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion \TrayNotify. ...
Step 3: Restart Windows Explorer.