help configuring ssh pub keys instead of passwords

[Brent]

On my freebsd 4.10 im trying to setup ssh2 to use dsa keys for authentication
instead of passwords ..

so far i have done

edit /etc/sshd_config

Port 22
Protocol 2
PermitRootLogin no
MaxStartups 5:50:10
X11Forwarding no
PrintLastLog yes
SyslogFacility auth
LogLevel VERBOSE
PasswordAuthentication no
PermitEmptyPasswords no
Banner /etc/issue
AllowGroups sshusers  <-- this exsists
	
# create some group that you can put OpenSSH users into
	Next, we'll open and edit /etc/ssh/ssh_config

[user at server /dir]#vi /etc/ssh/ssh_config

ForwardAgent no
ForwardX11 no
PasswordAuthentication no
CheckHostIP yes
Port 22
Protocol 2 

then i su to unpriv user and ran ssh-keygen -d

then i did 
cat id_dsa.pub > authorized_keys2

then copy the id_dsa.pub to a floppy so that i could transfer the dsa key to
the machine from which id be accessing the unix box.

i then tried to use the key from a winblows putty ssh client and i get the
folowing error when trying to login to the unix box

Unable to use key file "C:\id_dsa" (OpenSSH SSH2 private key)

Any help is very appreciated 

Thank you  Brent