Hi Pam There has been an ongoing argument on the subject of whether to turn off computers at night or when not in use for as long as I can remember A no brainer as far as I am concerned Anything you leave on will use more power and cost more than something you turn off As money is hard to come by and the worlds resources are finite why waste either I ask (I am not a greeny by the way) In terms of running cost, a tower or desk top will use more than a laptop and a flat screen uses less than a CRT monitor Having had some problems with our power supplier and not trusting their meters I bought a small device with calculates the power used and is programmable with the unit cost and will therefore work out the running costs of any plug in device I can't put my hand on my figures just now to give exacts unfortunately but there are plenty of discussions on the subject found with a google for computer running costs The usual arguments against switching your computer or monitor off are :- It uses more power whilst booting up (but as that takes a few minutes do not see that as a valid argument) It weakens components by switching on and off (as I have seen no evidence of that personal or otherwise find it hard to believe) I see no logical reason to leave anything on unless it is actually doing something Another point that seems to be often missed is that many things particular those using a transformer still draw power even when switched off, I have my computer, screen and all my peripherals into a multi block surge protected socket which in turn is plugged into a remote plug, one button and everything is off Nivard Ovington in Cornwall (UK) > If I leave my computer on all the time but turn off the screens at night > how > much more does it cost that to switch them off at night and on again in a > morning?? we have been having an argument about it so please if someone > could enlighten me please!!!! > > Pam