2. Navigate to the key (Wow6432Node for 64bit systems)
HKEY_LOCAL_MACHINE SOFTWARECitrixICAClientEngineLockdown ProfilesAll RegionsLockdownVirtual ChannelsKeyboard
3. Open Key: TransparentKeyPassthrough
4. Set the value to: Remote
5. Exit the Citrix receiver if it is started and log back into your Citrix desktop.
6. When the Citrix desktop session is the Active window, you will be able to toggle between the applications in that session with Alt+Tab