Please do the following to reset and connect the WLAN.
1: Choose "Network" in the Internet option, disconnect it and then delete the Connection in the "Manage".
2: Click "Create" to recreate the connection, choose "Local Area Network- Wireless", then Next.
3: Choose "Next".
4: Select Address Type, and then Next.
5: Browse Wireless Networks and then choose the one you want to use, choose the mode to be "infrastructure" and the Transfer rate to be "auto", and then Next.
6: Wireless Channel Settings, choose any channel.
7: If your AP is using the WEP or WPA encryption, you need to choose "Enable encryption" and then input the Key and Key index, choose Next.
8: Fill in the Name of connection, then choose Next.
9: You can choose the "Connect automatically at system startup" or "Start this connection when finished" if you want, and then choose Finish.