[ubuntu] Blank desktop after installing nvidia drivers

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http://ubuntuforums.org – I am using Ubuntu 12.10 64 bit and I my laptop has got Nvidia 525M switchable graphics card. My battery was not lasting longer and had a very high and constant fan speed. So I experimented with bumble bee and lastly downloaded graphics driver for my nvidia card from their site and installed it. After restarting, everything seems fine till the login screen but as soon as I log in, I only get a blank desktop. The launcher and the top menu bar, everything is gone. How, can I revert back or uninstall or do anything to get it working? I have installed and updated many softwares and I don't want t (Hardware)