Joe my computers run 24/7. However it is not power wasted as I do distributed computing, a worthy cause if you were interested.

I would suggest you do not use sleep mode but rather set the hard drive/s and monitor to go off in a given number of minutes of inactivity. There seems to be no science that can prove or disprove the advantages of either running or shutting down, it becomes a personal decision really.

Apart from the fans and hard drives which are 12 volts all the rest of the components inside the case are 5 volts or less. The monitor is more of course but you stop that after X minutes or hit the off button.

I could not imagine having to wait for a startup each time I came here.

I recommend leaving on, as owbist says...with a auto shut-back mode, during the period of time (day?) that you need to use the computer... Turn it off when you go to sleep (night). Its good to shut down and reboot periodically anyway, I believe.

Wouldn't you worry if you left home all day and the computer was left on? I worry about power failures, lightening, etc.

Jane I am very surprised you do not have one of those APC power backups on your system as you use it for business. Not that I had one for my first 20 years with computers LOL.

Those things never worried me. How often has lightening struck anything remotely near where you live? Of course it happens and of course I take the tiniest chance it might be my computer in the next storm. But if the lightening catches my home on fire I have still lost my computer even if it was shut down.

My model is to turn the machine off when it's not going to be used for hours... say at night when I go to bed, and when I leave my office for the day. Now, I have left the computer on many times, but turn it off if it isn't going to be use for at least 4 hours is my "line" and I'm sticking with it : >)

owbist, actually we were hit two years ago. It hit the phone box in our garage. It was amazing. I was home and it was a bad storm. I ran around unplugging everything, never thinking of the phone line or the cable. All our TV's were burned out (5 sets), and all the phones. The computers were saved because the phone line plugged into a power strip which I had unplugged. Insurance covered two of the tv's, but the others were goners.

Now when I hear thunder, I race around the house like a lunatic unplugging everything - including the cables and phone lines.

Jane

Laptop here runs 24/7. Sucks around 15watts at idle, another 10 watts when surfing, and maybe 50 watts if doing something serciously using cpu and hard drive.

However I just turned off a lan server to save the power it uses and the power costs of air-conditioning the heat load it generates too.

That Tower uses 130 watts at idle and 100 watts more when the monitor lights up for 5 minutes when remotely accessed, usually around 50 times per day.
It was costing me around $25 monthly during summer months in power used and heat gain that the a/c had to cope with. Of course I'll miss that heat when it gets cold on somedays. But its expensive heat.

We live in an area with frequent power outages and the surges that occurs when it comes back on. I understand that this will cause the surge protector to wear out. It happened to us. One of our computers was ruined. The other one which was on a newer protector was OK. So ever since then, Ours is not left on.

A couple of personal observations and opinions:

On and off is not the problem for a system, it's the cooling and the heating of the components which is a negative. It is far better to leave a system up all day than to boot it up continuously during the day. Of course hibernation/stand by is an option if your system handles the function appropriately. Many do not.

Leaving systems up and running costs money. The hourly rate is quite small, but if you have multiple systems and peripherals on around-the-clock it does add up. I conducted a personal test for my two "always on" systems versus one on only when needed (in the garage) and the other shutdown at night. My conclusion was a savings of just over $2.00 a month.

Excluding mandatory reboots, the best response to a finicky system is still a reboot. However,the theory of an occasional reboot comes from the era of Win98. Win98 became unstable if it was left on continuously so the recommended tip was to reboot daily. XP and Vista do not require this action.

Beautiful as it may be, lightening is not your friend. I would have to agree much depends on where you live. I live in rural America and have seen lightening storms with such intensity it is amazing. The problem for electronics is not just a direct or near hit, it is also the distant hit which hits a telephone pole. The charge will run the electric and telephone lines into homes, particularly the telephone lines as they are narrower in gauge with less resistance. Surge protectors are just that, surge protectors. Nothing man-made will protect against lightening totally. The best advice is disconnect when necessary.

As far as the original premise, personal choice.

DA

Not only do we turn them off, we unplug the surge protector or at least turn it off. We have been hit by lightening twice (once at home, once at the office). At the office it took out the surge protectors, the computers, the phones, the outside service and elec meter was a smoking black hole but the building did not burn. At home the TV's and TV accessories, computers, phones, and of all things a water bed were toast.