Can't connect to wifi - TP-LINK 300Mbps Wireless N ADSL2+ Modem Router TD-W8960N

Try turning off all encryption in the wireless router, delete the SSID's wireless profile in your computer, then connect to the SSID with no encryption. Windows should warn you there is no encryption, and it may limit your connection speed to 54Mbps (802.11n requires WPA2/AES encryption).

But if it then connects OK like that, you know the problem is/was an encryption mismatch.

In that case, switch the wireless router back to WPA2-Personal or WPA2-PSK with AES encryption, delete the newly-created wireless profile for your wireless router's SSID in your computer again, and connect to your WiFi with encryption, being careful to enter the WPA2 passphrase (8 to 63 characters) correctly when prompted.