On my Toshiba laptop I had something like this happen, and it turned out to be that I'd accidentally pressed a combination of keys that disables WiFi. On my Toshiba laptop it's Fn+F8, but your Lenovo probably has something different. Check your user guide to see.
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Good luck.
Hi Guys.
I've been having a weird wifi problem since last Friday. For some reason my laptop can't connect to any Wifi network anymore. Every time I try to connect I get the following messages:
1- checking network requirements
2-Can't connect to this network
I've tried everything I found online and nothing worked:
1-Uninstalling and reinstalling the wireless drivers. Event with different versions
2- Did a windows system restore
3-Turning wireless driver on and off
4- Restore the computer to its factory state using the Lenovo OneKey recovery
5-Scan the computer with McAfee and Malwarebytes antimalware for any threat.
If I connect using ethernet, everything works perfectly.
Computer Info:
-Lenovo G50-70
-Model: 20351
-Windows 8.1 - 64 bit
-NIC: Realtek RTL8723BE Wireless LAN 802.11n PCI-E
I some how believe that this issue is related to some Windows 8.1 update that messed up the wireless driver. How ever I'm not sure if the updates are desinstall with the lenovo system restore.
Another thing that caught my atention is that if I go to: Device Manager-> Enter the properties of Realtek RTL8723BE Wireless LAN 802.11n PCI-E -> Advance. There are some missing Properties in the list, like Network Address. I'm not sure if that is important.
Please let me know if there is any other info you guys need.
Regards

Chowhound
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