1. Run in the Terminal as admin 
net stop sshd
cygrunsrv -R sshd
net user

2. Delete the user "sshd" by running this command
 net user sshd /DELETE

4. Run this "rm -R /etc/ssh*"
5. Shut down any running cygwin processes.
6. In windows explorer delete the cygwin folder in C:\cygwin.