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System won't boot with nvidia driver enabled
I am new to Ubuntu. I installed Ubuntu 11.10, and downloaded the nVidia GEForce 8400 GS Graphics card driver from the official site. It was a .run file, and then I entered the TTY3 interface (Alt+Ctrl+F3) and installed the graphics card as a superuser. After that, the normal GUI of Ubuntu is not coming. I did few restarts, but some lines which says "Starting Bluetooth [OK] and Checking Battery status... [OK]" something like that are displayed, then nothing happens. Please tell me what to do. Thanks