I use AutoIt to write file associations to the registry. After that I need to rebuild the shell icon cache so the new icons get updated. I can´t find an AutoIt built in function and don't know how to make my own. Here is my script for 7-Zip. I use it on my unattended windows installation. #NoTrayIcon $g_szVersion = "7-Zip AutoIt v3 Script 1.0" If WinExists($g_szVersion) Then Exit; It's already running AutoItWinSetTitle($g_szVersion) $7zPath = RegRead("HKLM\SOFTWARE\7-Zip", "Path") Di