Connecting DB: Getting error message as "Data source name not found and no default driver specified

When i try to connect oracle db i m getting the error message as "Data source name not found and no default driver specified".

i m tried installing 64 bit and 32 bit ODBC driver but still no luck.

Below ex: I have updated the right Host , username and password.

I m able to connect same db using selenium but not with test complete.

"Driver={Microsoft ODBC for Oracle}; " & _
         "CONNECTSTRING=(DESCRIPTION=" & _
         "(ADDRESS=(PROTOCOL=TCP)" & _
         "(HOST=host)(PORT=1521))" & _
         "(CONNECT_DATA=(SERVICE_NAME=odcms_cms));UserID=username;Password= password;"