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:
Virtual Box gives a lot of issues when it comes to bridge adaptor. I had the same issue with Virtual Box for windows 10. I decided to create VirtualBox Host-Only Ethernet adapter. But I again got issues while creating the host-only ethernet adaptor. I decided to switch to vmware. Vmware did not give me any issues. After installing vmware (and after changing few settings in the BIOS) and installing ubuntu on it, it automatically connected to my host machine's internet. It was able to generate it's own IP address as well and could also ping the host machine (windows machine). Hence, for me virtual box created a lot of issues whereas, vmware worked smoothly for me.