If there are any WiFi weirdnesses in Windows it is always worth deleting the stored Profile for the particular router SSID as a first step.
Open a command prompt - as administrator may be necessary depending on your setup.
Find the name of the SSID you want to delete the profile of and delete it. You will have to put the password in again.
e.g.
C
Users\harry>netsh
netsh>wlan
netsh wlan>show profiles
Profiles on interface Wireless Network Connection:
Group policy profiles (read only)
---------------------------------
<None>
User profiles
-------------
All User Profile : iPhone
All User Profile : Huawei E5372s-32
All User Profile : AndroidAP
All User Profile : SKY97324
netsh wlan>delete profile name="Huawei E5372s-32"
Profile "Huawei E5372s-32-064" is deleted from interface "Wireless Network Connection".
netsh wlan>
netsh wlan>
netsh wlan>exit
C
Users\harry>
You can alternatively type the whole netsh command as follows, but I seem to find the above method easier.
Whole command in one shot example.
C
Users\harry>netsh wlan show profiles
Profiles on interface Wireless Network Connection:
Group policy profiles (read only)
---------------------------------
<None>
User profiles
-------------
All User Profile : iPhone
All User Profile : AndroidAP
All User Profile : SKY97324
C
Users\harry>
Good luck.