Hi,Hannes and dataMiser
i have been using 64 bit machine . and os as well 64 bit . the following connection string is working in vb.net .
Dim con As New OleDbConnection("Provider=OraOLEDB.Oracle;Data Source=infinity-db:1521/rptprod;User Id=MDMFIROZ;Password=MDMFIROZ_142")

but the following connection string is not working in vb6 Application . let me know some valuable comment please .
 constr = "Provider = OraOLEDB.Oracle;Data Source=infinity-db:1521/rptprod;User Id=MDMFIROZ;Password=MDMFIROZ_142"