Wifi not working (need help)

I have just switched over to ubuntu mate but my wifi is not working, it shows up in BIOS but it does not work I have tried the key that enables and disables the wifi but nothing has changed, I can only connect to the internet via wired connection to my router, can anyone help please?

Open “Additional Drivers” and install the missing drivers.

No additional drivers available, when I had regular ubuntu it was just a case of switching it back on

Which version of Ubuntu MATE are you using and what kind of Wireless card are you using?