Troubleshooting QuickBooks Error Code 15106 involves identifying why payroll updates fail to install. The most common causes include insufficient Windows admin permissions, corrupted update files, or aggressive antivirus software marking processes as unsafe. Users can try disabling User Account Control settings, repairing QuickBooks Desktop, or temporarily disabling antivirus programs to fix this problem. If you are tired of repeated update failures and need an immediate resolution, contact +1-866-408-0444 for expert troubleshooting and successfully complete QuickBooks Desktop payroll updates without facing Error 15106 again in the future.