I originally marked this as off topic, began replying and then noticed that the crash was with winss, which seems to indicate that the laptop is crashing due to part of OneCare. I recommend contacting support.
How to reach support (FAQ) - http://social.microsoft.com/Forums/en-US/onecareinstallandactivate/thread/30400b52-7f26-4ba0-bc18-17e305329d90
-steve
Microsoft MVP Windows Live / Windows Live OneCare, Live Mesh, & MS Security Essentials Forums Moderator