|Your system is hibernating/sleeping.|
You can turn the feature off in control panel-power options.
edit* Sorry, the guy above beat me to it. Wasn't there when I started to type.
AMD Phenom II x6 BE 1090T @ 3.8GHz 1.40V
8GB GSkill Ripjaw @ 1333 7-7-7 1.60V
HIS Radeon HD6850 IceQX Turbo 1GB CrossfireX
OCZ Vertex+ SSD
2x WD Blue SATAIII
CM GX 650