well, my desktop connects to the wireless router via eithernet cable and the router is connected to the modem , i also suspected that IP conflict might be the issue but i have disabled and enabled the connection and done repair on it so it would change the ip as its automatically gained but i always get the same problem.
last night i tried to uninstall my driver of the Eithernet card and reinstalled it , it worked fine and hopefully it will be working today, if anything happens then i will get back to you with the latest feedback.