trust me, turn it off. if you do leave it on, unles you have some serious cooling, and amazing virus and firewall protection, then no harm in leaving it on, but leaving it on will shorten its life, so says the machines.....and a national study over the course of leaving it on the computers died in a few years, 3-5. the on off ones never died. so it is just safer to turn it off. i turn mine off whenever i am not at it, and i even disconnect the internet. why? so nobody can acces my computer remotely, because no matter what you have if someone has the ip adress and name of you computer, theres a telnet. always better to be safe.snipercomplete

3-5 years? a computer is only good for 3-5 yrs anyway. it needs to have upgrades after that amount of time. and for this environment crap, how many of you actually strive to save the environment? none of you do. leave it running if you have the software to keep it from being hacked.