Can you make a database (Oracle 7.3) consisting of several .DBF files into one .MDF file (Oracle dump file) in Windows 7 or so.
Is there a tool that can do that "export" ?
I'm afraid you can not do that. .DBF is Oracle format while .MDF is MS SQL format. The only way is to run a tool which connects onto both databases and copies data online. Or you have to dump OracleDB into plain text file(s).