I get that message all of the time!!!!  I don't have much memory on my desktop and every single time I render anything I get that message. I have to hide huge amounts of a figure and render in sections and assemble in a graphic program!  Sometimes it will take me 5 to 8 renders or more to render a single clothed figure, and forget raytracing!!! I have to do all of my metal effects in post work because turning raytracing onto anymore than 2 gives me that message.

And you're right. Once that happens the only way out of it is to press "reset" button on the computer, at least on my computer.  CTRL ALT DEL won't even shut my computer down after I get that message.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi