Putty

Putty Is an open source SSH terminal application write for Windows & Linux/Unix systems, licenced under the MIT licence.
 * Putty's Download Page
 * Putty's FAQ

Where does PuTTY store its data?
On Windows, PuTTY stores most of its data (saved sessions, SSH host keys) in the Registry. The precise location is HKEY_CURRENT_USER\Software\SimonTatham\PuTTY and within that area, saved sessions are stored under Sessions while host keys are stored under SshHostKeys.

PuTTY also requires a random number seed file, to improve the unpredictability of randomly chosen data needed as part of the SSH cryptography. This is stored by default in a file called PUTTY.RND; this is stored by default in the ‘Application Data’ directory, or failing that, one of a number of fallback locations. If you want to change the location of the random number seed file, you can put your chosen pathname in the Registry, at HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\RandSeedFile You can ask PuTTY to delete all this data; see question below.

On Unix, PuTTY stores all of this data in a directory ~/.putty.

What does PuTTY leave on a system? How can I clean up after it?
PuTTY will leave some Registry entries, and a random seed file, on the PC (see question A.5.2). If you are using PuTTY on a public PC, or somebody else's PC, you might want to clean these up when you leave. You can do that automatically, by running the command putty -cleanup. (Note that this only removes settings for the currently logged-in user on multi-user systems.)

If PuTTY was installed from the installer package, it will also appear in ‘Add/Remove Programs’. Older versions of the uninstaller do not remove the above-mentioned registry entries and file.