I'm usually able to stay on all day, (yea, i know i need to get a life) but now i'm crashing after a few hours. i'm using windows7 home pro and the singularity sl viewer, version 1.7.2. I don't know what more info i can or should give you. Anything else you need to know, just reply. Thanks for taking the time to read this...if you did, that is. :)