Dell's Community Support Forum is very good and has bailed me out of a few jams more than once. It pointed me to the link to the Windows Code 19 problem that everyone found about the same time. Now I'm out of suggestions & stumped. Cold boots CAN work wonders sometimes though...but hammers can too :)
By cold boot, do you mean turn it off and then wait a few minutes before restarting?
If so, I have done that twice.