Thanx, unfortunately the link wasn't helpful.
A while back, I was trying to work out another problem and it was advised that some drivers be updated. Specifically, I installed sp36491, 38834, 42635, and 45112. These are specific to HP laptops and the NVidia GForce card. It may very well be that this current problem began post-install. Is there any way to roll them back? I can't find them in computer/manage/device manager.