I ran into this problem as well.
Chances are, your WiFi drivers are incompatible with Windows 10. I'd check online to see if your manufacturer has released a compatible driver, or get on the phone with tech support to see if they can direct you to the correct driver downloads. You will need to load the driver installer onto a flash drive from a separate computer though.
If this doesn't work, and there are no compatible network drivers for your laptop, the only option you really have is to roll back to Windows 7.