Block user on wireless network

Hi guys,

I would like to know please is there is a way to block a user on a wireless home network who is already connected. The reason is because when i find my speeds going low because i am sharing it with many guys in my flat, i would like to temporarily disconnect that computer till my downloads are done with.

Is there a network monitoring software which is a freeware or any special commands i can use in my command prompt.

I know that in command prompt, the command : "net view" shows the users connected in the network. Is there any way i can block them or something....

Thanks in advance..