[NBLUG/talk] Can't ssh to Ubuntu using PuTTY

[Roger House]

I'm a Linux newbie who recently installed Ubuntu desktop on an older PC.
The installation was essentially trival, and so far I'm having a lot of
fun with Linux.  However, I have run into one issue which I haven't been
able to resolve via books and Google.  The Linux machine and a Windows
machine are both hooked up to a router which provides Internet access via
DSL.  I can access the Internet just fine from both machines.  However,
when I try to use PuTTY on the Windows machine to ssh to the Linux machine
I get "PuTTY Fatal error:  Network error:  Connection refused".  On the
Linux machine itself I tried "ssh localhost" and got the message
"connect to host localhost port 22:  Connection refused".  I am assuming
that some config file somewhere is not allowing remote logins, but I
have been unable to track this down.  Any help will be appreciated.

Roger House