I´m using a small batch-file for this:
taskkill /f /IM explorer.exe
CD /d %userprofile%\AppData\Local
DEL IconCache.db /a
This delete the icon-cache.
Production: NX10.0.3 MP16, NX11.0.1 MP4
Development: Batch and VB Testing: NX12
Thank you for the suggestion! It cleaned the icon cache, but icons were changed to some other than it was shown in the picture. I have manually fixed those from the properties of icon shortcut.