all of a sudden ora-12560

11g 11.2.0Windows 7/64

I'm trying to connect to my ORCL instance

SQPLUS /nolog

connect / as sysdba

ERROR:
ORA-12560. TNS: Fehler bei Protokolladapter
C:\app\kuku\product\11.2.0\dbhome_1\NETWORK\ADMIN>tnsping orcl

TNS Ping Utility for 64-bit Windows: Version 11.2.0.1.0 - Production on 18-OKT-2
011 12:35:54

Copyright (c) 1997, 2010, Oracle.  All rights reserved.

Parameterdateien benutzt:
C:\app\kuku\product\11.2.0\dbhome_1\NETWORK\ADMIN\sqlnet.ora


Adapter TNSNAMES zur Aufl÷sung des Alias benutzt
Verbindungsversuch mit (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = localho
st)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl)))
OK (0 ms)


Any clues?

Thanks in advance,

Christoph