Because you are familiar with Linux commands, you have installed Oracle virtual machines in the Win7 environment and installed unbuntu-server in the virtual machines. Unbuntu installation process is smooth, because it is a piece of cake, the basic choice of default installation.
Environment:
Win7
Oracle VM VirtualBox 5.0.20
Ubuntu-14.04.1-server
After installing Ubuntu ifconfig view Ubuntu IP address for 10.0.2.15, not the same network segment as the host's IP address. Putty Connect Ubuntu has always appeared network error:connection timed out. See for various reasons SSH is not turned on.
Then turn on SSH:
First, install the sudo apt-get installation openssh-server
Then, confirm that Sshserver is starting PS-E | grep ssh appears with sshd as the description starts. If manual start is not started: Sudo/etc/init.d/ssh start
After starting the connection still appears the same problem, connection timed out.
Later to see the internet said Ubunutu IP and host IP is not a network segment will not even, my affirmation is not a network segment, this time find the virtual machine network settings, select the bridge segment connection, and then connect can be connected.
Putty Connect to Ubuntu in Oracle VMS