Sophos Update Manager log viewer displays error 1601

  • Article ID: 109801
  • Updated: 06 Mar 2013


The Sophos Update Manager is failing to update and the update manager details pane in Sophos Enterprise Console shows the following error:

80040401 Software Update Failed

The SUMLog shows the error:

Installer returned 1601

First seen in
Sophos Update Manager


This error can be caused when the Windows Installer service is not accessible

What To Do

First ensure that the Windows Installer service is not disabled (Start | Run | Services.msc)

If the service is not disabled, then re-registering the MSIEXEC.EXE usually resolves the issue:

  1. Open a command prompt (Start | Run | Cmd and press enter)
  2. In the command prompt type:
    msiexec.exe /unregister
  3. Then type:
    msiexec.exe /regserver
  4. Attempt to update again.

If you need more information or guidance, then please contact technical support.

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