Disabling Diffie-Hellman on IIS Servers ProcedureAdd or modify the following Registry key on each web server: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\ SCHANNEL\KeyExchangeAlgorithms\Diffie-Hellman\ Enabled = 0 (DWORD value) Restart the web server for the changes to take effect.