- Open up the Terminal
- Run the following comman
defaults write com.apple.desktopservices DSDontWriteNetworkStores true
defaults write com.apple.desktopservices DSDontWriteUSBStores true
- Restart your Mac or log out and back in.
defaults write com.apple.desktopservices DSDontWriteNetworkStores true
defaults write com.apple.desktopservices DSDontWriteUSBStores true