Please try the following on the problem lenovo laptop:
Please click on Start, then right-click on Computer, then click on Manage, then click on Device manager, then open/expand Network adapters and right-click on each of the items under it and click on Uninstall and confirm. Then restart the computer.
Please click on Start->All Programs->Accessories, then right-click on Command Prompt and click on Run as administrator. Then type:
netsh winsock reset , and press Enter.
ipconfig /release , and press Enter.
ipconfig /flushdns , and press Enter.
netsh int ip reset netshlog.txt , and press Enter.
Then restart the computer and check.
If needed, download and update the latest wireless driver at http://consumersupport.lenovo.com/ot/en/DriversDownLoads/Drivers.html
Please let me know if there is still any issue later. Thank you.