function _IsClassRegistered
lparameters tcClass
#DEFINE HKEY_CLASSES_ROOT    -2147483648
#DEFINE ERROR_SUCCESS		0	&& OK

DECLARE Integer RegOpenKey IN Win32API ;
	Integer nHKey, String @cSubKey, Integer @nResult

DECLARE Integer RegCloseKey IN Win32API ;
	Integer nHKey

local lnKey
lnKey = 0
llRetVal = ( RegOpenKey(HKEY_CLASSES_ROOT, tcClass, @lnKey) = ERROR_SUCCESS )
if llRetVal
  RegCloseKey(lnKey)
endif
*vfp7
*CLEAR DLLS 'RegOpenKey', 'RegCloseKey'
return llRetVal