It's a dell ubuntu. But I don't know why I can't do:
which is my local-ip.
You should start with some basics.
Ok, need some more info from you first:
Can you ssh in from any other pc?
What software are you using on the win client? Putty?
Are you getting a connection refused or a time out error?
Openssh-server is not installed on most distros automaticly, did you install it on your "dell Ubuntu" box? Without it you can't get remote access. 'Sudo apt-get install ssh' should do the trick.
Can you ping the ip?