Isee that your notebook does not have support for official upgrade to windows 10 so acer will not provide driver support. However, searching the internet I found this post which reports the same issue and suggests a solution. You can read it and try to see if it will work for you. They suggest to download a driver from the broadcom webpage, and then manually upgrade your drivers.
I got the 64-bit files, unzipped, stored the 3 files in a known folder, open Device Mgr, go to Broadcom Netlink adapter, go to Update Driver, point at the location where I stored the 64-bit version of driver files. When I hit Next, I get a msg "The best driver software for your device is already installed" ... "Windows has determined the driver software for your device is up to date."
Thanks for the feedback and your help with this frustrating problem. It is sad it is so difficult to get resolution for a 4 y old laptop. And, looking at various postings it seems this has been a problem also a year ago when people upgraded to W10. When the laptop was 3 y old....
This date is 4 days before the date on the driver now installed by MS (2015-08-18). Is this the reason why the Broadcom driver proposed by "Trouble" on the referenced MS Forum is rejected ( -internet-connection.1031/)?
You can try to go to update driver software --> Browse my computer --> Let me pick.... ---> Here click on have disk ---> select the place where you extracted the driver (go exactly to the 64bit folder or 32 bit folder depending what OS you have) ---> then select Gigabit ethernet.
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