I usually keep my PC running 24 hours a day as well, however I turn it off during exam time and test time during the night... apparently the more silent it is the better sleep you get (at least that what I heard once, but to me it looks like it's kind of true). So if I have a big test then I usually turn it off so that I might get better sleep and hopefully pass the test.

On other days, I keep it on and use it as an Alarm clock, so that I can wake up to the exact song I want to. This is kind of better than an alarm clock so I need to keep my PC on. I could turn it off... but I just like to keep it on .

24/7 here as well.

Have met some people who claim it is not healthy to leave a computer running in your bedroom overnight, not sure how correct they are in their thinking.

I on it to use it, then i leave it off.

it depends...if i'm using it till morning, i leave it on...but if nobody's using it anymore, i turn it off so i can save on energy...

I always shut down my computer when I am done for the day so that it saves electricity. Plus it makes the house more quiet!

I keep it On from morning till night , just shut it down before I go to bed

i shut mine down whenever im not using it as its a laptop and a fire hazard more so than a pc i think xxxx

My computer is always on. I am to lazy to wait for a boot up but it don't hurt much. :P

I usually leave mine on... especially if I have downloads, scans or something else time intensive going... On the odd occasion I turn it off..

in regards to any electronics or electical device with solder connections they are better to be left powered up the the expansion an contraction of a solder point becomes weak an brittle over time when its tempature goes from warm to cold then eventully breaks like the filament in a light it will burn 10 to a100 percent longer if left on there are bulbs that have been burning well over 50 to 70 years there not special there just never turned off an are on a very stable power grid keeping them at a constant tempature so it is best to leave powered up things are changing an more things are built that have solderless connection just for that reason but not everything an not your pc so for general shelf life of your pc leave it on an run a cool screen saver with a sort of animation to it it will keep pc active an as for stanby thats good if your going on vacaction or long term time with no fuction it keeps board warmed up but uses less power hope this is insightful