i have an i7 with 16 GB of RAM and a fairly new vid card, nvidia with 1GB.  my desktop is 2560 x 1600 so im thinking maybe it's because my renders are so big?  the display window is usually 1600 x 1400 or so, but sometimes i render larger and shrink it down later.

This has been happening to me for years; if the scene is fairly simple it doesn't crash, but a huge closeup tends to crash more often than not, it just hangs on "Cancelling"

ill upgrade my SP maybe that will help.