Find this key:
HKEY_LOCAL_MACHINESOFTWAREVMware, Inc.VMware Tools
or, if you’re on x64:
HKEY_LOCAL_MACHINESOFTWAREWow6432NodeVMware, Inc.VMware Tools
Change the ShowTray DWORD value to 0.
Since this is in the HKLM hive it will take precedence over the same setting under HKCU.
If you want to disable the icon only for the logged on user, change the same value but now under HKCU.