When enabling the "energy saver" feature that turns off your hard disks after a certain defined period of time, what exactly happens to your PC? If I have certain downloads going on the computer and this feature comes into effect, do these downloads stop as well?

No, the hard disks only turn off after a certain period of inactivity. So if there are any downloads on your computer, they get finished, then your computer waits the period of time, then if nothing else happens, the hard drives switch off. That's what I think happens. So you should be safe.

it depends, my sisters comp has really conservative powersetings, i kno cuz i built it for her, so one time when i was defragging her harddrive and left, evrything went into powersaving mode after fifteen minutes and the defragging got screwed up and the pc froze. But most modern pcs should not have this problem and the powersaving features will do no harm except if lets say you have a long download going so you sit on the couch and watch tv periodically checking the monitor, but it will turn off if the suspend option is enabled. your download will continue but you will have to get off of your lazy butt to reactivate the monitor and check your progress. ^(-.-)~~~]>:}>