QuickBooks Payroll Update Error 15241 occurs when the QuickBooks Desktop File Copy Service (FCS) is disabled or malfunctioning. This error prevents the payroll update from installing correctly. To resolve it, open QuickBooks and go to the Services tab. Locate QuickBooks FCS, right-click, and select Properties. Set the Startup type to Manual or Automatic, then restart the service. Ensure QuickBooks is running as an administrator and update the payroll again. If the issue persists, reinstall QuickBooks or contact QuickBooks support for additional troubleshooting and resolution steps.