Dell XPS 12 Ultrabook has network connection problem using WIFI after Windows 10 upgrade

I have a Dell XPS 12 Ultrabook laptop which was running extremely well on Windows 8.1. When Microsoft prompted me to register upgrade to Windows 10, I hesitated but in the end, I registered for it. In the last few months, I was prompted many times to upgrade to Windows 10 but I just ignored and delay the upgrade as much as possible as I need to do work with the laptop and I cannot afford to have problems after upgrading.  To my horror, Microsoft forced an installation of Windows 10 this morning without permitting me to delay it and right after the upgrade, I cannot connect to my current network. So I have no access to the internet and I am currently typing this complaint using another PC. I noted that the laptop can connect automatically to the network when I switch off and on my router but the connection will last only a few minutes and then it will be disconnected. I tried connecting it and the message I get is "Can't connect to this network". I checked with "ipconfig /all", the wifi indicated media disconnected. I checked with Dell support website and downloaded and installed a newer driver but the problem persisted. Apparently surfing through the internet, this problem is faced by quite a few and all the suggestions to fix it do not work (after I have tried them).

Please help.