Please provide more information. The more the better, but what I think would be useful there is the boot log which you can find in the system log (/var/log/syslog)
** Changed in: powernowd (Ubuntu) Importance: Untriaged => Medium Status: Unconfirmed => Needs Info -- freezes pc when launched https://launchpad.net/bugs/48792 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs