Leaving your computer on... overheating? lifespan?

Utter BS, I've had computers that lasted more than 4 years being turned-off when not in use, before I got rid of them or they just died. Running a computer 24/7 would result in:
1. Increases the hard drive's chance of failing since its mechanical components are always running.
2. Increases the chance of failure on the motherboard as the electrolytic capacitors are always running and they could dry up quicker.
3. Although unlikely, processor life may be shortened either because of electromigration or the heat that it is stressed under for 24/7.

Buy only quality components and you'll reduce the chance of failure drastically. Buy cheap components and they could break in a few months or maybe even tomorrow.

Either way is fine.

Some time ago it was not good for harddrives to bee switched on and off too often because when it is running heads are flying on the pillow of air, when sitched off they are touching the disk surface until it spins up when switched on. If You would use PC for 10 min, then switch it off then on again 5 min later ... this could cause hdd to fail prematuerly. This is no longer case in modern hdd's.

Motherboaords now mosltly use solid state capacitors which cannot dry out, but PSU's still use electrolytic caps which may dry out by time. On the other hand there is power surge every time You turn PC on which put stress on PSU and m/b power components and may shrten lifetime.

Either way You choose it will become morally obsolete before it fails from running 24/7 or often switching. Not saying that it will not brake as it may very well brake for other reasons.

I say switch it off for night or extended periods when not in use, but don't shut it if You know You might be using it in 30 min time.

I have mine running for a day and I put it to sleep when I go out or whatever and shut it down over the night.

Before I worried about on / off vs. running 24 x 7, I'd worry about buying faulty components... Get the fan fixed. THEN worry about whether turning your PC off at night is a concern.

I've never seen a study that came up with any conclusions either way. Personally, I turn mine off every night, as my partner is a light sleeper and even the wee noise from my PC will keep her up... No issues for me, so far, other than the one night I forgot!

I shutdown my workhorse PC pretty much only when I go on vacation or when I need to work on it. It's, I don't know, 8 or 9 years old - AMD Barton core, FX-5700 GPU.

I have an OC'd Q9550 for games and multimedia. And I'm planning on migrating the workhorse stuff to a Q6600 machine.

i usually keep my computer on for the entire day and then just turn it off when i sleep... that can't be that bad right? I don't turn it on for 30 min then shut it off and turn it back on like 20 mins later.

I would get the fan fixed ... but it's so annoying... my scythe mugen-2 is freaking huge and i would have to remove it again -_-"
My computer components are fine, i can go into bios and stuff... i'm just waitin on my vista to come in.

I don't know what to do >.> Maybe i'll just leave my computer on and just turn it off once in a while just to give it a break or somethin.

This is a pointless thing to worry about. Things break eventually. Sometimes sooner rather than later. Pondering whether or not they broke because they ran too long or because they were power-cycled one too many times is worthless.

Do the world's energy resources and your power bill a favor and put your computer into sleep at night. Do your peace of mind a favor and buy quality parts.

Edit: Oh and do your sanity a favor and BACKUP.