A quick answer is because you are running a lot of stuff. For example, just a quick glance I see you have AT LEAST 7 processes running for your istuff, (ipod, itunes ect), and you have another 5 (for now that number will grow) processes running for your symantec. You are also running speedfan. Why? You are running the nVidia app that goes the same thing. Kill one or the other. The nVidia one not only will tell you the temps of you cpu, gpu, RAM, and HDD (I think, HDD, it may be some other component) but also give you other info about each component. Adawrae runs 3 or 4 as does Spybot.
Your ASUS Mobo comes with assorted crapware like the aacenter.exe, AInap, AEADISVC.exe, turboV.exe, and the mysterious AsSysCtrlService.exe I say mysterious because although it is obviously an ASUS exe, no one seems to know what it does and ASUS isn't saying even on their forums).
You Adode (is it the free or paid BTW) is running several, some which are unnecessary. Did you install the True Imagwe Back-up or is that crapware that came installed on your computer? If you didn't install it then you can get rid of it and the timountermonitor.exe will go away.
Soundmax EXE is either a realtek driver or a Trojan, I was confused and didn't spend enough time to verify either one. But I would check here
, and then ask someone before you delete it, because I also found somewhere else that it is a necessary component for sound if you have Soundmax. Since you also have smax4pnp.exe running, I'm going to assume that you DO have Soundmax and shouldn't stop this, but again, ask a real malware pro.
But as you can see you have a bunch of stuff running and each one uses a couple (or more) processes. There are a few you can stop. Jusched.exe for example is a totally useless process that Java inflicts you with. It runs constantly to check if there is a Java update. Java updates about once a millennium but that process runs constantly and constantly checks. It can also be a stone cold witch to stop. I don't know how many processes the bit torrent uses, but as you use it more and it allows viruses and other malware into your system it will slow soon slow you down.
I would HIGHLY recommend to get rid of the Symantec crap, unless it is the high dollar commercial version. Sysmantec (IE Norton) does not play well with Vista, especially 64 Bit Vista. They claim they have fixed it, but they have been claiming that since their original claim that it worked with Vista in the first place proved to be false. I really do not understand how a product (norton/Symantec) can have so many problems with another product (Vista) and still be so widely used and so widely installed by computer manufacturers, and so blatantly ignored by people AS a problem despite all the documented cases. they seem to be able to shift blame for all problems it causes on hardware and other software. I had it when I built this system (also Vista64). I STILL use symantec on my XP system, so it's not like I hate Symantec or anything, it just doesn't work with Vista.