Alastairstevenson, thanks for your reply; I've done that and then some. I don't even get a mouse cursor. I even tried plugging in a USB keyboard and hitting keys to wake it up.
I have since rebooted my NVR so I've gotten in but then next time it freezes I' stuck again.
I read another post suggesting rebooting on a regular basis, could that be my problem, not rebooting often?