Recover a ArcServe Backup of Oracle

Hai, we use ArcServe for our Backups. Now i try to recover a Oracle Database which is backed up with ArcServe.
Unfortunately it doesn´t work.

Here what i tried:
i created a database. with same name, same configuration ...
then i shutdown the oracle tasks (windows system) and delete all files of this "temp"-database
then i restored the database out of our ArcServe backup.
finaly i tried to start the database.

i got the following messages:
SQL> startup
ORACLE instance started.

Total System Global Area  612368384 bytes
Fixed Size                  1298184 bytes
Variable Size             167772408 bytes
Database Buffers          440401920 bytes
Redo Buffers                2895872 bytes
Database mounted.