Reference: regKeyExists
regKeyExists(RootKey, KeyName) returns True if the registry key named KeyName (a string) exists under RootKey. RootKey is "HKCU", "HKLM, "HKCR, "HKCC", "HKPD", "HKDD", or "HKU".
regKeyExists(RootKey, KeyName) returns True if the registry key named KeyName (a string) exists under RootKey. RootKey is "HKCU", "HKLM, "HKCR, "HKCC", "HKPD", "HKDD", or "HKU".