I stand corrected. Hibernate is indeed better as it completely turns off everything. But again, sleep/standby will not overheat anything as it will turn off the harddisk, CPU, etc, except the RAM, which is consuming negligible power and negligible temperature compared to cpu, which at that time is already turned off. checked my XP, can't find hibernate, I clicked shutdown and I have only the following options: Log off Shutdown Restart Standby don't know whether i disabled something by accident, the reason why hibernate is not displayed in my xp.