String -> HKEY

const
  HKEYNames: array[0..6] of string =
    ('HKEY_CLASSES_ROOT', 
     'HKEY_CURRENT_USER', 
     'HKEY_LOCAL_MACHINE',      
     'HKEY_USERS',
     'HKEY_PERFORMANCE_DATA', 
     'HKEY_CURRENT_CONFIG', 
     'HKEY_DYN_DATA');

function StrToHKEY(const KEY: string): HKEY;
var
  i: Byte;
begin
  Result := $0;
  for i := Low(HKEYNames) to High(HKEYNames) do
  begin
    if SameText(HKEYNames[i], KEY) then
      Result := HKEY_CLASSES_ROOT + i;
  end;
end;