OK so my upgrade to Windows 10 new version may have gone smoothly, but a thing I noticed after booting to the Desktop was that there was no Network icon in the Notification Area of the Taskbar and there was now way I could connect to the Internet – whether it was to my cable broadband connection or the WiFi.
No internet access in Windows 10
I opened Windows 10 Settings > Network & Internet, and clicked on the Status link. Here the Network status was showing a No internet access message.
If you see this message, you need to click on the Troubleshoot button. When you do that, the Windows Network Diagnostics Troubleshooter will open and try to fix the problems.
One the job is done, see if it has helped.
This worked for me.
Post updated for Windows 10 April 2018 Update
These posts offer additional troubleshooting suggestions: