thanks a lot Shiva - got error message: "The database installer reported an error. DIAGNOSIS: Some database applications might still be running........." - only when I checked in the sapinst_dev.log did the real cause become clear which was - "
HKEY_LOCAL_MACHINE\SOFTWARE\SAP\SAP DBTech' does not exist on the 'localhost' host." - your suggestion worked for me. Thanks again
Prashant