Questions about ssh

For more information about ssh-general Linux technology-Linux technology and application, see the following. My VM is ubuntu8.04. I just installed openssh and want to access linux from windows.
But when I test ssh in a virtual machine, there is a problem. As follows:
I typed ssh localhost in the terminal and returned read from socked failed: connection reset by peer.
The result obtained by debug is: ssh-vvv localhost

OpenSSH_4.6p1 Debian-5ubuntu0.6, OpenSSL 0.9.8g 19 Oct 2007
Debug1: Reading configuration data/etc/ssh/ssh_config
Debug1: Applying options *
Debug2: ssh_connect: needpriv 0
Debug1: Connecting to localhost [127.0.0.1] port 22.
Debug1: Connection established.
Debug1: identity file/home/listar/. ssh/identity type-1
Debug1: identity file/home/listar/. ssh/id_rsa type-1
Debug1: identity file/home/listar/. ssh/id_dsa type-1
Debug1: Remote protocol version 2.0, remote software version OpenSSH_4.6p1 Debian-5ubuntu0.6
Debug1: match: OpenSSH_4.6p1 Debian-5ubuntu0.6 pat OpenSSH *
Debug1: Enabling compatibility mode for protocol 2.0
Debug1: Local version string SSH-2.0-OpenSSH_4.6p1 Debian-5ubuntu0.6
Debug2: fd 3 setting O_NONBLOCK
Debug1: SSH2_MSG_KEXINIT sent
Connection closed by UNKNOWN

Let's take a look. Why?