It just sets up a vpn, like if you were part of the physical network. If he is at work then he does not need Hamachi because he is already part of the network.
The only time he needs it is at home so that a computer outside of the physical network can join it.
To read the msn conversations he might just be using vnc or some such software. Or your friend has her msn conversations saved (msn has an option to do this) and it is being saved to a shared folder.
It just sets up a vpn, like if you were part of the physical network. If he is at work then he does not need Hamachi because he is already part of the network.
The only time he needs it is at home so that a computer outside of the physical network can join it.
To read the msn conversations he might just be using vnc or some such software. Or your friend has her msn conversations saved (msn has an option to do this) and it is being saved to a shared folder.
Hamachi is a centrally-managed VPN system, consisting of the server cluster managed by the vendor of the system and the client software, which is installed on end-user computers.
Client software adds a virtual network interface to a computer, and it is used for intercepting outbound as well as injecting inbound VPN traffic. Outbound traffic sent by the operating system to this interface is delivered to the client software, which encrypts and authenticates it and then sends it to the destination VPN peer over a specially initiated UDP connection. Hamachi currently handles tunneling of IP traffic including broadcasts and multicast. The Windows version also recognizes and tunnels IPX traffic.
Each client establishes and maintains a control connection to the server cluster. When the connection is established, the client goes through a login sequence, followed by the discovery process and state synchronization. The login step authenticates the client to the server and vice versa. The discovery is used to determine the topology of client's Internet connection, specifically to detect the presence of NAT and firewall devices on its route to the Internet. The synchronization step brings a client's view of its private networks in sync with other members of these networks.
Source(s):
http://en.wikipedia.org/wiki/Hamachi
Got them of net hope it helps