Software for silent monitoring a remote computer from a network

I need a software for silent monitoring a remote computer in my network.
I want to watch all the activities done from that computer.
I don't know if this is possible, but in my network there is a remote computer, and I want to be able to record all the activities from the moment the user logs onto that computer.
Is this possible?
Can you help me with this, because I have never done this before and I need step by step instructions on this issue.
Thank you in advance Techyv.
