Oracle VirtualBox - Failed to open create the internal network

Introduction

Are you getting the error "Oracle VM VirtualBox - Failed to open create the internal network" for the VirtualBox Host-Only Ethernet Adapter while logging into a virtual machine created in Oracle VirtualBox with Windows 10 operating system ?  If so, please try the solution below.

Solution

1. Open Control Panel>>Device Manager.
2. Expand “Network Adapters”.
3. Notice that “Virtual Box hosts-only adapter” is present.
4. Right click on the adapter and select “Uninstall”.
5. Complete the uninstall process, by removing all supported files. (This is very important. If you do not remove all the files, virtual box will use same registry entries/drivers after reinstalling).
6. After uninstalling the Virtual box host-only adapter, Uninstall Virtual box completely. This uninstalling should be done by “Virtual Box” installer. Do not do this directly from Control Panel>> Programs and Features/Add or remove programs”.
7. Restart your PC.
8. Do a complete fresh install of Oracle VM VirtualBox again.
9. Open Control Panel>>Network and Internet>>Network Connections.
10. Right click on the Virtual Box adapter and select “Properties”.
11. Make sure “Virtual Box NDIS6 Bridged Networking Driver” is selected. If it is not selected, then check the checkbox and click on OK. 
12. Open Virtual Box application and then try to startup the VM. It should start without any issues.