If you have trouble with changing wifi password and cannot find and option to forget or clear an old wifi password on windows 8, here is a simple solution:
1. Open command prompt screen by pressing windows + r and type "cmd" enter.
2. run this command (profilename is the name of the wifi):
netsh wlan delete profile name='profilename'
Thats all! Now when you try to connect it will ask your key again.
