Oracle Express services not starting

Question

today I tried to install Oracle Express 10g on Windows 7 64bit (and 11g also). Unfortunately I ran into some problems. First of all, I noticed that the home page is not being loaded. Then I checked the services with "lsnrctl services" and noticed that there were some services that were not started.

C:\Users\myuser>lsnrctl services

LSNRCTL for 32-bit Windows: Version 10.2.0.1.0 - Production on 19-JUL-2011 21:02:21

Copyright (c) 1991, 2005, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
  Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0
         LOCAL SERVER
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0
         LOCAL SERVER
The command completed successfully

I tried to reinstall Oracle several times - no success. I'm currently trying to access the database only locally.

Solutions I tried so far were :

change the HOST in tnsnames.ora to "localhost" or "."

change the HOST in listener.ora to "localhost" or "."

change the SQLNET.AUTHENTICATION_SERVICES in sqlnet.ora to "NONE"

I tried the last one because I changed the windows password recently, if this is relevant at all. No success so far.

I tried to install oracle on another 32bit machine with Windows 7, everything went fine.

I'm using Windows 7 Enterprise, 64bit, no service pack, SQL Server 2008 is installed.

I used Oracle SQL Developer in order to test the actual connection. The following error was thrown :

Test failed : Listener refused the connection with the following error ORA-12505; TNS:listener does not currently know of SID given in connect descriptor. 

listener.ora :

    SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = C:\oraclexe\app\oracle\product\10.2.0\server)
      (PROGRAM = extproc)
    )
    (SID_DESC =
      (SID_NAME = CLRExtProc)
      (ORACLE_HOME = C:\oraclexe\app\oracle\product\10.2.0\server)
      (PROGRAM = extproc)
    )
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    )
  )

DEFAULT_SERVICE_LISTENER = (XE)

tnsnames.ora :

    XE =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = XE)
    )
  )

EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )

ORACLR_CONNECTION_DATA = 
  (DESCRIPTION = 
    (ADDRESS_LIST = 
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC_FOR_XE)) 
    ) 
    (CONNECT_DATA = 
      (SID = CLRExtProc) 
      (PRESENTATION = RO) 
    ) 
  ) 

UPDATE

I still cannot resolve this issue. Additionally, I found out that there is no registry entry created by the Oracle express installation. Anyone?