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I've been running Ubuntu for some time. Last night I installed the updates that automatically download periodically and shut down. This morning the machine will only boot to the command prompt. I've tried all the "fixes" I can find on-line without success. The startx command brings up a message "API mismatch: the NVIDIA kernel module has version 304.88 but this NVIDIA driver component has version 173.14.35.".. How do I make sure both are the same? What else can I do to get this machine to boot the GUI again?