How long is too long to leave your computer on? I don't like to keep my laptop on for more than a few hours but I keep my desktop on for days at a time. Is this bad or can it harm things?

i generally turn my pc off every morning. i leave it on at night to listen to music as i sleep.

so its usually on for about 9 hours straight during that time and even then i feel like i should turn it off sooner.

most things arent built to run for days at a time, unless otherwise stated, and your computer is no different. you have to give the parts a chance to cool off that happens when the computer isnt in use. but thats just my opinion.

Yeah, thanks, I figured. I just get into the habit of turning it off in the morning or at night.

if all components are sufficiently cooled (fans!), constant running wont harm them. but by using they wear off, just like clothes. hence some component's life-span will be reduced. most likely to happen with hard-disks or certain parts on your mainboard. but not too significantly, we're talking about some 20.000 or 30.000 hours of average (!) operating time with hard disks (a year is 8760h).

When I'm downloading or uploading DVD torrents, I will leave it on for days at a time. Otherwise I turn it off every night.

Does anyone have more info about this? Since reading this thread I've been kinda worried about my Hard Disc dying. My computer is like 3 years old, and more and more often now I'm leaving it on for days at a time to download/uplaod torrents.

What about sleep mode...?

I leave my computer on, and if I dont use it for about 20 min, it will pretty much shut down, (i dont hear anything, and nothing is on the screen) all that happens is the little 'on' light blinks....then I just go move my mouse and my computer is just how I left it....programs open and all....

Is it ok to leave it like this for days at a time...?? Thanks!

If you're not going to be using your computer for a while, it's best to shut it down or put it into sleep mode. The whole reason people used to say to leave your computer on was because when old hard drives were shut down, the read/write head used to set down on the disk itself, potentially causing damage after many on/off cycles. Todays hard drives do not do this, so there is little of damaging your hard drive from turning your computer off.
Leaving your computer on for days at a time without it going into sleep mode (where the hard drive spins down) will eventually wear out the bearings in the hard drive, but eventually could be a long time.
Basically, it comes down to this: If you're ul/dl'ing, I wouldn't worry about leaving your computer on. If you're leaving it on for no reason, shut it down or put it to sleep and save energy. Turn off monitors when not in use. Schedule your Windows updates and anti-virus updates to occur at startup or at a time when you know your computer will be on. And lastly, keep back-ups of anything you don't want to lose. Power surges, lightning strikes, and hard drive failures always find a way to happen at the worst possible time.

Mine's on 24/7. The only time I'll shut it off is when I'm going out of town.

i also leave mine on 24/7 it stays on sometimes for months without me restarting or shutting it down. the only time it gets restarted is when the power goes out, or i install a program that asks for a restart. i have never had a problem. like someone said earlier the parts have run times of thousands and thousands of hours.....so i dont see it running out before i get a new one.