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Putty

Clear Session Information and Host Keys from Registry

SUMMARY: For privacy, if you no longer plan on using Putty, remove information it stores in the Windows Registry.

The Putty terminal software stores information in the Windows Registry at key: My Computer\ HKEY_CURRENT_USER\ Software\ SimonTatham. This includes session configuration information and SSH Host Keys, useful to help determine if a remote computer accessed via SSH has changed or if there is a possibility a "man in the middle" attack attempt is occurring.

If you plan on deleting Putty from your computer and possibly donating or giving away your machine, you may wish to remove this information from the Registry for privacy reasons. The Putty registry entries include the list of sites to which you access via SSH, and you may not want this known by third-parties.

To perform a cleanup, execute the following command at the DOS prompt or via "Start" - "Run":

putty -cleanup

If Putty is not in your system PATH, make sure to include the full path to Putty when executing this command.

You will be presented a dialog box similar to the following:

Putty cleanup warning dialog box

If you click "Yes", all Putty-related registry entries plus a random seed file "putty.rnd" (normally located in your "Application Data" directory) will be removed.