I have a brand new G770 and also have the issue described and was directed by Lenovo support to reformat the laptop using the "OneKey rescue" button. This took 20 minutes and wiped any software I had installed. This did update to
The wifi connection has improved but spotty wifi connection remains. I have other pc's in the office which show no wifi issues.
That's sill and unfortunately sad. The silly part is that the part description clearly indicates the part. No mystery there. But sadly Lenovo does not let you change the NIC card. At least without voiding the warranty. Worse yet Lenovo keeps a "whitelist" in the BIOS that allows only some (one?) device to be used. Lenovo support says the company consider the WLAN adapter an "internal part". (Why one might ask use the min-PCI standard and fake it to be properietary - really bad PR polciy if you ask me). Maybe the other list parts will work and maybe your BIOS will hate you. And yes, the driver list does include Intel drivers, but apparently for another planet. Lenovo, you are not making friends with this.
Why do I care? Because Intel WIDI to remotely display your laptop on an HDMI TV only works with select Intel WLAN card (one used by Lenovo on other models, maybe even this one according to repair manual instructions). I feel trapped between two manufactures abusing their power, IMHO, and not in alignment either.