I have a problem establishing wi-fi connection in Ubuntu. Wired connection is working fine (all updates installed), the problem is I can not connect to wireless. I can see a lot of networks around me, but I can not see my router. Sometimes I can see it, I try to connect but connection fails. I have also tried connecting to my hotspot, but no success. Other machines are using wi-fi with no problem. I am a newbie to Linux, so if anyone can guide me how to install drivers, etc. Please help.