Thanks for contacting us today and I'll be happy to help. Putty us used
for ssh connection and the problem is that none of your user are
currently set to allow ssh connections.
Please log into the Web Panel and got to the following page.
https://panel.dreamhost.com/index.cgi?tree=users.users&
From there you can edit your users and change them from ftp to shell.
Shell users can connect via ssh so just wait a few minutes after you've
updates the users and you should be able to connect via putty without
issue.
I hope that helps a bit. If you have any further questions please let me
know.