This is the second time I updated mu Ubuntu 12.04 and the result is when I turn my computer back on all seems to de doing well. Then I get the Ubuntu emblem right before the system would come up. Instead I get command lines asking me to log in, then, after logging in I am left with command line screen, no ubuntu. This happened about 3 weeks ago after update, then i just did a reinstall. Now it happened again. Why will it not go though with a full boot of the system? What command line got corrupted or erased? The system has been great until this. Like I said it is 12.04, 64 bit.