"The Windows Installer Service Could Not Be Accessed" error message when installing the Symantec Endpoint Protection client.


Article ID: 178013


Updated On:


Endpoint Protection


The Symantec Endpoint Protection (SEP) client installation fails at the very beginning of the installation process, with an error that indicates the Windows Installer Service can't be accessed.




  • In SEP_Inst.log an error appears as 'Failed to connect to Server......'
  • If SEP client installation is launched using Symantec Antivirus.msi, an error appears:
    "The Windows Installer Service could not be accessed. This can occur if you are running Windows in safe mode, or if the Windows Installer is not correctly installed. Contact your support personnel for assistance."



The Windows Installer is corrupt.


These steps are provided for your convenience. For further assistance in troubleshooting possible operating system corruption, please contact Microsoft support.

  1. Download and install the latest Windows Installer for the OS in use.
  2. Execute Symantec Antivirus.msi. If the error still appears then proceed further.
  3. Open a command window: Click Start, click Run, type cmd in the Open box, and then click OK.
  4. Type msiexec.exe /unregister, then press Enter.
  5. Type msiexec /regserver, then press Enter.
  6. Execute Symantec Antivirus.msi.  Installation should then be successful.

To check the permissions on the registry key, perform the following steps.
NOTE: Be sure to back up the registry before proceeding:

  1. Click Start, click Run, type regedit in the Open box, and then click OK
  2. Click the following registry hive:
  3. On the Edit menu, click Permissions.
  4. If SYSTEM is not listed in the Group or user names list, click Add, make sure that the local computer name appears in the From this location box, type system in the Enter the object names to select box, click Check Names, and then click OK.
  5. Click SYSTEM in the Group or user names list, and then select the Full Control check box under Allow in the Permissions for SYSTEM box.
  6. Administrator account should be added as well
  7. Click Apply, click OK, and then quit Registry Editor.
  8. Restart the system.


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