I just upgraded my laptop from Windows 7 to Windows 10 and found that I am unable to start Virtualbox VMs configured with a bridged adapter.
See the configuration below:
I faced the same problem today after updating the Virtual Box. Got resolved by uninstalling Virtual Box and moving back to old version V5.2.8
My very simple solution that worked: select another networkcard!
If it doesn't work, repeat steps and try yet another network adapter. The very basic PCnet adapters have a high succes-rate.
Good luck.
Go to your net card. Go to properties and then "Add service", which? This: VirtualBox NDIS6 Bridged Networking Driver
Reopen Virtual Box
My Windows 10 machine was automagically updated today. Looks like the "Windows 10 Anniversary update" When I restarted Virtualbox my server with a bridged adapter showed same as OP. I tried rerunning the VirtualBox installer (it did a Repair) - that did not fix the issue. I tried running the installer again as Admin (it did a Repair) - that did not fix. I ran the installer and selected UnInstall, then ran it again to Install. And the Network adapter settings looked good. Server started and connected to my network as usual. Whew. Hope this helps someone.
Uninstall then run the setup program again but this time as Administrator. Make sure the VB bridge driver is selected during installation.
In Case some one is looking and none of the above resolves your issue : https://forums.virtualbox.org/viewtopic.php?f=6&t=90650&p=434965#p434965
placing the WIFI as the first adapter [MTDesktop, AllowALL] and the LAN WIRED [MTServer,AllowAll] as the second adapter. In the Guest machine I disable the First Adapter in Adapter Settings. I can then ping internal, external whatever.