I watched which registry keys change when checking/unchecking the Do not show me this console at logon checkbox and it turns out that it changes the key:
HKEY_CURRENT_USERSoftwareMicrosoftServerManagerIf the DWORD value DoNotOpenServerManagerAtLogon is set to 0, the Server Manager will open at startup; if set to 1, you won’t see it!
Hope this works for you! 😉
