After installing 4.03.094.2 on the host pc, device drivers can't be updated or installed from other places than the default, because the according window where a different path can be entered is missing.

After uninstalling the software everything is ok!

This is the NComputing software which lock this feature. Don't know why they did do that ... But in parallel, you can modify the registry with regedit :
Go to [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion]
Modify or create the "DevicePath" (REG_EXPAND_SZ) according to your need.

After that, you can restart the device driver wizard.