Ping preload is not permitted, what could be the reason

Try setting your network to bridged, so it picks up a network address from your lan, and you will be able to gain access to it.

I fixed the problem by removing the hidden physical network adapters.

This can easily be removed by opening the command prompt with administrative access and typing the following command:

set devmgr_show_nonpresent_devices=1

start devmgmt.msc

When the Device Manager loads, from the File menu, expand the View and select the Show Hidden Devices option. This will enable and show any old un-used devices in the window. From here, expand the Network Adapters node and you can right click on the devices which are extra and delete them accordingly.

Not sure why I had to do this, maybe because this 2003 Server was originally on this hardware. But everything works correctly now. I can ping, and the AV clients can receive updates correctly.