New PC goes 2 standby even though Skype is on

like the title says.
i've noticed that when i have utorrent working, because of the constant upload etc. , the pc doesn't go to standby.
What i mean by standby is that the pc doesnt do anything, the light in the front is filickering slowly, and the internet connection is off. When i move the mouse, the pc springs to life , followed by the internet connection , and in a few seconds i'm connected to the internet.
Needless to say, i believe u understand the flaw with this - skype gets disconnected even though i want it to remain on, and i'm guessing the same would happen with facebook. As much as power saving is indeed, important i want my computer to not go into this mode , at least not while there is a program that requires internet or even chat websites.
How can i do that ?
thax people.

As far as I know - and I will be very happy if anyone tells me otherwise - Windows goes to Standby (or Sleep, or Hibernation - depending on the power plan settings that whs pointed out) after certain "inactivity time". But what exactly constitutes this inactivity? Unfortunately it's mostly keyboard and mouse use. At the same time some programs know how to prevent standby and then you can leave the computer alone with the program running. Others do not - and apparently Skype belongs to that category.

The only way I know how to fight this strange feature is to edit the power plan to set this timing delay to "never". This means that your PC will never go into any sort of sleep or hibernation or standby, unless you explicitly tell it so (by clicking at the start button). This is how my machine is set up. Yes, sometimes this leads to unnecessary waste of electricity - sometimes I forget to turn the machine off when I leave the house and then it will stay on. But at least I can write a program and set it run for as long as necessary without having to come and move the mouse every now and then. To me, that's important.

But, like I said, if anyone has a better idea, I would be most interested to try it out.

my pc isn't english, so if i try to translate, what i found is:
under POWER CONSUMPTION OPTIONS in Hardware and Sound, i pressed the blue link "Change the sleep timing of the pc"

and there are 2 options:
Turn off monitor - set to 10 min.
Make PC sleep - set to 30 min

i changed sleep option to 1 min and checking it right after clicking REPLY
brb dude :)

ok , even though skype is on, after i changed the settings like i wrote here, the pc went to sleep after a minute of mouse inactivity.
It appears that Unifex has got it all right. Apparently, programs such as uTorrent tell the PC , to keep being awake. Dunno if its because they're uploading or whethere there's more to it, but those programs keep it working, just like they should if u want to seed a torrent all night long.
However with skype its different.
This program cant make the pc remain awake so i must set it to NEVER, unless anyone else enlightens me and Unifex, with a brilliant way to make the pc understand - WHENEVER THERE IS NOTHING USING INTERNET OR DOING ANYTHING ELSE, then u can sleep after a set amount of mouse inactivity. "
If the pc would sleep in the middle of burning process? Gee i wonder what the people who made this feature thought, dont they know that people give the pc a task so it woukd do it while they go and eat at the kitchen?
Well anycase as i said , altough this option is amazing because the PC is saving power and being quiet, if it's gonna disconnect me from sites or anything else, cant allow it....
If anyone has a magic solution for me and for Unifex i'd appreciate it.
thax

and whs, THANK YOU, for letting me know about stopping this feature.