Look at the bottom of the adapter card itself (the green PCB board). You will see a sticker or a printed label that says something like Ver: 3.0 . This number dictates exactly which driver your Windows 10 system needs. If you try to force a V1 driver onto a V3 card, it simply won't work.
Let us know your card version (check the sticker on the card itself) in the comments below. If you are still stuck, double-check that you have inserted the PCIe card fully into the slot—it sounds simple, but it happens to the best of us.
Here is the hard truth: Because the TL-WN951N is a legacy product (classified as "End of Life" or "End of Service" in some regions), TP-Link never released a specific, dedicated driver package labeled "Windows 10" for this device.
Find the Atheros Driver In the left manufacturer list, scroll to Atheros Communications Inc. In the right model list, look for: