i purchase Dell XPS L502X with Windows 7 Professional x64 pre-installed and fully genuine. but my bad luck on youtube i found a key to upgrade windwos 7 professional x64 to ultimate x64 and worked. but after some days message appeared that this copy of windows is not genuine. So, i tried 100 of activators to activate the windows but not a single activator or loader working.only Windows 7 RemoveWAT 2.2.5 by Hazar worked but it did not make it genuine just removed the activation trial period. Now, please help me in this case. i'll be very thankful to you. Regards.