The main problem is somebody sniffing the network. At least when the traffic is encrypted the attacker now has to unencrypt it. Depending on your encryption this could take minutes or months.
How big of a risk does authenticating over an unencrypted line pose. Depends on what your authenticating to, if its only your YouTube account then you will probably dont have much to worry about, if your authenticating with your bank for perhaps a money transfer - then this could lead to problems.
Many IM tools send unencrypted data across the P2P network.
Port 80
A network security test is all-important with regard to a secure internet connection. It prevents unauthorized access and prevents stealing of sensitive data.
In general, yes. The WiFi password is a network security key. There are some special systems, however, which require a different network security key to access the internet, sometimes even if you have a wired connection.
Domain profile
"transactional traffic" is the righ answer.
Yes, especially if you don't encrypt your communications. Packet sniffer programs do this all the time.
A Domain profile offers the least security. A Private profile offers moderate security and a Public profile offers the highest security.
there are two types of connection network: Point-to-Point Connection and Multipoint Connection
Peer to Peer network (Microsoft calls it a Workgroup). Does not require cable for connection, can be wireless. Is appropriate for up to 10 computers. Each computer in a Peer to Peer network keeps its own security access database. That means, each connection to the computer must have an account on that computer.
This is a problem with the security settings on your wireless connection. To do what you were doing when the error code appeared, change your wireless network security type to WEP, or disable security (not recommended).
Some adapters require you to predefine settings for such networks including security network phrase, name of the network, type of connection type of security and so on.