Unable to start sshd

I'm new to Ubuntu and trying to start sshd but having a lot of problems. I've tried uninstalling and reinstalling ssh by running sudo apt-get remove openssh-client openssh-server and sudo apt-get install openssh-client openssh-server. When I run sudo service ssh restart I get:

stop: Unknown instance:
ssh start/running, process 3638

sudo service sshd start gives me unrecognized service.

When I run ps -A | grep ssh I get nothing. Running ssh localhost gives me a connection refused.

Solution 1:

Try purging before install:

sudo apt-get purge openssh-server
sudo apt-get install openssh-server

Solution 2:

Ubuntu ssh service will start with ssh, not sshd.

Try:

 sudo apt-get remove --purge openssh-server
 sudo apt-get install openssh-server

Then try:

sudo service ssh restart   

To check its status:

sudo service ssh status

Config file can be found at /etc/init/ssh.conf

Detail about remove and purge:

remove - Does NOT remove including configuration files

purge - With Purge command, the configuration files are also deleted.