My computer freezes at 0% when building lightmaps

I have a GTX 980 4gb of ram
Intel Xeon X5650 @ 2.67 2 procs
32gb of ram and a 500gb harddrive

windows 7 service pack 1

currently when i build my lighting my scene crashes freezing my computer. I even shut off all the lights except for one and had the same issue. The scene when building the lightmaps crawls the ram all the way up and then back down. when the ram gets down to about 21gb it then freezes my computer to where my computer but my mouse still functions.

i am not sure why all those pictures didn’t end up being showed as embedded images rather then links