To address this type of installation failure, always make sure that no other software is being installed or uninstalled when the SEP installer is running. If no other install service is running, try rebooting the machine and initiating the installation again. If the installation continues to fail reporting that another installer service is running the following steps may work around the issue.

  1. Start the registry editor by navigating to the start menu and clicking Run, then typing regedit and clicking the OK button.
  2. Back up the registry by choosing the Export option from the File menu, make sure to check the All radio button under the Export Range section, then select a location in which to save the backup and click Save.
  3. Once back in the registry editor, navigate to:
    • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\Inprogress
  4. Delete the Inprogress key (make sure to delete the entire key and not only the values contained within the key).
  5. Open the Task Manager.
  6. Navigate to the Process tab.
  7. Search the list for any occurrence of msiexec.exe, highlight any entries found and click End Process.
  8. Try the installation again.