Hi JOYROY :)
This issue is very easy to solve. It's due to the corruption of the wireless network profile you have saved on your system for that network. All you need to do is to delete the network connection profile, and then reconnect to your WiFi network.
See the article below to learn how to delete a wireless network profile on Windows 8.1:
http://www.7tutorials.com/how-delete-forget-wireless-network-profiles-windows-81
Let me know if you have any questions.
Yoan