problem with oracle database connectivity !!

Hi,
I have a 200MMX machine with 64MB or RAM and 2.5GB harddisk and it has windows 95 OS and Windows NT 4.0 installed on FAT...and I am using Oracle 7.3 engine for NT....
and when I opened Database Explorer and try to connect with Oracle engine it gives me an error which is
ORA-03121...No Interface driver connected...
                        function not performed  Alias: Oracle-db
                        BDE Error: 12548  [$31] [$4]
                        Network type unknown

so can u please give me a solution of this problem....I just want to connect Delphi 3.0 with Oracle 7.3 database and want to access Oracle table within delphi...

Your help in this matter will highly be appreicated...

Thanks
Zahid