Uninstalling Cygwin

Here's the rough steps on how to do it, according to the official FAQ.


 * 1) Stop and remove any cygrunsrv services
 * 2) Stop all Cygwin processes and unmount any filesystem's mount with the   command.
 * 3) Delete the Cygwin root folder and all subfolders.
 * 4) Delete the Cygwin shortcuts on the Desktop and Start Menu.
 * 5) Remove cygwin binary path from your Windows search path, and delete the CYGWIN system variable.
 * 6) Delete Software\Cygwin keys from registry.

Removing SSHD serv
From: http://pigtail.net/LRP/printsrv/remove-cygwin.html

Windows
Exit from cygwin terminal and follow below steps:

To remove Cygwin sshd in the cleanest possible way:

cygrunsr -E sshd and cygrunsrv -R sshd

OR

open command prompt and run below command.

>sc delete sshd

Press enter.

delete the folder c:\cygwin and all its sub-folders

remove the Environment Variable ' CYGWIN' 

edit the Environment path accordingly

Start...Run... regedit and delete these two registry trees

"HKEY_CURRENT_USER" --> Software --> Cygwin

"HKEY_LOCAL_MACHINE"--> Software --> Cygwin

Go to Control Panel, Category View, Performance and Maintenance, Administrative Tools, Computer Management.or click Start...Run...compmgmt.msc delete the sshd user if it exists in the "System Tools" - "Local Users and Groups" - "Users" section.

Thanks to Dave Abrahams of Boost Consulting for the sshd user account deletion hint.