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Listener losing instances after PC restart

user548177May 7 2026

I have just moved all my work from a Windows 10 PC to a Windows 11 PC. The new PC is supposed to be a mirror image of my old PC. This includes a copy of Oracle 21c Express Edition and Oracle SQL developer 24.3. I have a problem with Oracle on my new PC as the listener only shows 1 instance when it should show 5. I deinstalled and then reinstalled 21c on my new PC and everything was back to normal. That is until I restarted my PC the next day. I could not connect to my Oracle database because of the message “ORA-12514: TNS:listener does not currently know of service requested in connect descriptor." I ran lsnrctl status and it showed the following:

LSNRCTL for 64-bit Windows: Version 21.0.0.0.0 - Production on 07-MAY-2026 18:39:25
Copyright (c) 1991, 2021, Oracle.  All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=lenovo2)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for 64-bit Windows: Version 21.0.0.0.0 - Production
Start Date                07-MAY-2026 18:08:55
Uptime                    0 days 0 hr. 30 min. 30 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Default Service           XE
Listener Parameter File   F:\Oracle-21c\homes\OraDB21Home2\network\admin\listener.ora
Listener Log File         F:\Oracle-21c\diag\tnslsnr\AJM-LENOVO2\listener\alert\log.xml
Listening Endpoints Summary...
 (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1521)))
 (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC1521ipc)))
Services Summary...
Service "CLRExtProc" has 1 instance(s).
 Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

It is supposed to read as follows:

LSNRCTL for 64-bit Windows: Version 21.0.0.0.0 - Production on 07-MAY-2026 16:59:45
Copyright (c) 1991, 2021, Oracle.  All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=lenovo)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for 64-bit Windows: Version 21.0.0.0.0 - Production
Start Date                07-MAY-2026 16:56:36
Uptime                    0 days 0 hr. 3 min. 19 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Default Service           XE
Listener Parameter File   F:\Oracle-21c\homes\OraDB21Home2\network\admin\listener.ora
Listener Log File         F:\Oracle-21c\diag\tnslsnr\AJM-LENOVO\listener\alert\log.xml
Listening Endpoints Summary...
 (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=AJM-LENOVO)(PORT=1521)))
 (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC1521ipc)))
 (DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=127.0.0.1)(PORT=5500))(Security=(my_wallet_directory=F:\ORACLE-21C\admin\XE\xdb_wallet))(Presentation=HTTP)(Session=RAW))
Services Summary...
Service "972805166862470e8292abeb88b33fbe" has 1 instance(s).
 Instance "xe", status READY, has 2 handler(s) for this service...
Service "CLRExtProc" has 1 instance(s).
 Instance "CLRExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "XE" has 1 instance(s).
 Instance "xe", status READY, has 2 handler(s) for this service...
Service "XEXDB" has 1 instance(s).
 Instance "xe", status READY, has 1 handler(s) for this service...
Service "xepdb1" has 1 instance(s).
 Instance "xe", status READY, has 2 handler(s) for this service...
The command completed successfully

Here is a copy of my tnsnames.ora file as it was created during the installation process:

# tnsnames.ora Network Configuration File: F:\Oracle-21c\homes\OraDB21Home2\NETWORK\ADMIN\tnsnames.ora
# Generated by Oracle configuration tools.
XE =
 (DESCRIPTION =
   (ADDRESS = (PROTOCOL = TCP)(HOST = lenovo2)(PORT = 1521))
   (CONNECT_DATA =
     (SERVER = DEDICATED)
     (SERVICE_NAME = XE)
   )
 )
LISTENER_XE =
 (ADDRESS = (PROTOCOL = TCP)(HOST = lenovo2)(PORT = 1521))

ORACLR_CONNECTION_DATA =
 (DESCRIPTION =
   (ADDRESS_LIST =
     (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
   )
   (CONNECT_DATA =
     (SID = CLRExtProc)
     (PRESENTATION = RO)
   )
 )

Here is a copy of my listener.ora file as it was created during the installtion process:

# listener.ora Network Configuration File: F:\Oracle-21c\homes\OraDB21Home2\NETWORK\ADMIN\listener.ora
# Generated by Oracle configuration tools.
DEFAULT_SERVICE_LISTENER = XE
SID_LIST_LISTENER =
 (SID_LIST =
   (SID_DESC =
     (SID_NAME = CLRExtProc)
     (ORACLE_HOME = F:\Oracle-21c\dbhomeXE)
     (PROGRAM = extproc)
     (ENVS = "EXTPROC_DLLS=ONLY:F:\Oracle-21c\dbhomeXE\bin\oraclr.dll")
   )
 )
LISTENER =
 (DESCRIPTION_LIST =
   (DESCRIPTION =
     (ADDRESS = (PROTOCOL = TCP)(HOST = lenovo2)(PORT = 1521))
     (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
   )
 )

Why is it that after reinstalling 21c there are services I can connect to, but after restarting the OS they disappear?

This post has been answered by user548177 on May 9 2026
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Added on May 7 2026
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