ok, so here's my problem. I run a pc business and a 'customer' has been having problems with one of my machines (which i built) for a few months now. Apparently the machine will random reboot, either on startup, emails, or generally anything, sometimes will go into sleep mode and sometimes shut down (with fans still running), i have had the machine in my office, plugged it in and it ran for over 24 hours non stop with no issues, at all, this has happened so many times now and the customer is very irate (which is not helping!) i can't fault the computer as it runs perfectly on my office desk, yet when the customer takes it home and plugs it in, the problem starts, might run for 5 minutes or 5 hours then shut down. I have suggested to him to check his power points and extension cables etc but he insists they are all good. Since i can't fault the machine and will have to return it - yet again, to this customer with a no fault found, I expect that it will be an ongoing issue, as i say, it runs fine in my office so ps, ram and processor can't be the problem? system temp is 31oC and processor temp is 40oC... the customer insists it is on a desktop with adequate ventilation. Anyone got any ideas here as im sure the customer will not be happy that his computer works! (at least when its with me!