New computer get bogged down.

Ok most likely this isn't a spyware issue, as the computer is three days old. I built this system and it is very quick, but I just ran into a problem
While copying a DVD web surfing and playing music the computer loads up and gets alot slower, as well as the playback gets noise in it.

3.0 ghz p4 with ht
1 gb pc3400 crucial

My question is: is there a program so I can see the ram throughput, and if that is where the bottle neck is.

I would have thought 1 gb of ram would have been more then enough for anything I wanted to do, but maybe not ? When the system is on its own its very fast, but multi tasking is not working.