[Solved] Network Monitoring

Hello!

I've come here to seek wisdom from you.

The problem:
I have 3 computers at home connected throu a router. Often, when I'm busy at my computer someone else uses the other PC/'s.
And ofcourse, when they use alot of broadband by downloading, streaming, uploading they take not only theirs but mine speed
and stabilty of the net. So im getting pissed off and has to shout cause they download or something while im trying to work.

The question:
Is there an easy to use (doesnt have to be newbish, just skip the pinging and cmd commands please) software that will monitor exactly how much and which one of the
other computer is using of my broadband.

I was thinkin of something like
PC1[Boldor]: xxxxxkb up xxxxxkb down
PC2[xxxxx]: xxxxxxkb up xxxxkb down
well, u get the point.

This is my first post here and im not English in any aspect so please excuse my spelling.

Kind Regards
Boldor