I am using NORTON Antivirus.
I headed to the "device manager" and:
I uninstalled the network adapter named "Dell Wireless 1702 802.11b/ g/n
then I pressed "scan for hardware changes" and it installed it again but nothing happened.
I restarted the laptop and then I COULD CONNECT TO THE INTERNET!
I am still a complete ignorant what and why was that..
I am so sorry for the disturbance over here..