VirtualBox adapters greyed out
I tend to use my ESXi and/or Proxmox host/s for virtual machine testing and development, however VirtualBox is still a fairly solid alternative. In late 2022, VirtualBox introduced virtual TPM (vTPM) and secure boot.
As part of some recent testing, I deployed a Windows 10 instance with VirtualBox 7.0.10 and found that all available network adapters were available. Specifically, all were greyed out except for 'Adapter 4' which was unavailable. I couldn't click on anything, nothing was configurable. Nothing had changed from my previous 6.7 (?) install.
I found the following article and have reproduced the notes here in case the original source is unavailable.
BrianGillette posted;
Go to Control Panel -> Network & Sharing Center -> Change adapter Settings
Right click on your network adapter and pick "properties"
In the "connection uses the following items" box, at the bottom, click the Install button and select "Service" from the list and click the Add button.
A list of existing services will pop up. you want to choose the "have disk "option.
Once you have chosen the Have Disk option you will navigate to C:\Program Files\Oracle\VirtualBox\drivers\network and pick the "netlwf" item and add it as a service.
Close out of Virtual box if you haven't already, and re-open it. Now the adapter will be in the Network Adapter list for the Bridged Adapter field.