I have an older acer LAPTOP 7250 series. No matter what I do I can't get the wifi on. "Fn+f3" does not WORK. Manually it will not turn on. When I'm in the network setting I will click it to on but it shows that it will not turn on and stay on the off side. The driver is correctly installed and says it is working properly....any suggestions?Are you running Windows 10 on this laptop? I had some issues with Network DRIVERS with Windows 10 that state they work as in no complaints in Device Manager yet the driver clearly doesn't work. My fix for my friend with an older laptop that is running Windows 10 was to buy a new USB Wireless Adapter as for the Wireless Chipset in his laptop ended support at Windows 7 and the Windows 7 driver doesnt work under Windows 10.... Oddly enough though upon first install of 10 it worked ok, and then there were some updates and the update targeted the wireless adapter driver. He can BOOT his laptop on Linux and Wireless works no problems on the internal wireless that CAME with the laptop, so its an issue with Windows 10 stomping on his wireless driver with one that doesnt play well with the chipset.

If your not running Windows 10, I would suggest getting a modern Linux Distro on a USB stick or DVD and boot off of that and see if you can connect wireless through Linux. If it works through Linux but not Windows then you know its a driver issue. If it doesnt work under Linux then the radio might have died in that wireless adapter in which the cheapest and easiest solution is to add a USB Wireless Network Adapter that supports your OS. They are around $15 each after shipping. I have an EDMAX that works flawless for my friends laptop and I also used it to make an older laptop that never came with wireless a Pentium 3 800Mhz Dell Laptop I was able to get Wireless on with this USB NIC running Windows XP a few years ago. And that was USB 1.1 and not 2.0 and it worked.Laptop wifi cards are cheap.  I've been buying lots of replacements for older laptops.  Even brand new ones don't work or half work, i.e. 1 band instead of 2.