Hello.

I have encountered this problem in my notebook Lenovo B5400. I have installed dual boot Windows 7 and Ubuntu 17.04 both 32-bit systems. This problem started about a week or two weeks ago, when I have changed my primary connection "type" (before I used only wi-fi to connect to Internet and now it is primarily Ethernet cable).

My problem is this: when I boot into Ubuntu I cannot see any wi-fi access points (and the same problem with ethernet). So, before booting into Ubuntu I have to boot into Windows before and after that I may boot into Ubuntu and my wi-fi adapter works fine (the same with ethernet). I do not know where is the problem exactly, I have tried many solutions but they did not work properly or at all.

Now, I have booted into Windows so Internet works normally. If there is need to upload some outputs from Ubuntu, please write me.

Thank you.

Did you install the firmware of the WIFI adapter?

Yes, I have installed it, but it does not work.

And now, wi-fi does not work at all. In Software Update -> Additional Drivers I see 2 proprietary drivers which I use. But at the bottom of the this window there is written: 1 proprietary driver in use. (which is firmware for Intel processor.) Second driver for BCM43142 802.11 is checked but there is some sort of problem because it does not work.

Please, help.