Just upgraded the server from NT4 to WIN2000. Mada a complete backup from Oracle database and installed Oracle again (8.1.7)

Imported the database, and everything works, however when opening the DBA studio end trying to open the Schema nothinh happen (also no error!). When trying to do zhis from another client this works

I already tried to reinstall Oracl eagina, but still the same problem

Somebody knows what is going on?