Windows Server 2019 — IIS W3SVC service refuses to start after reboot — Fix & Prevention

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution — Primary Fix
7. Solution — Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

The World Wide Web Publishing Service (W3SVC) on Windows Server 2019 fails to start, returning all hosted sites unreachable. HTTP/HTTPS connections drop and dependent monitoring agents flag outages. Browsers display connection-refused while application pools remain idle until the parent service initialises successfully.

Environment & Reproduction

Reproduce by restarting W3SVC after an IIS configuration change or hostfix install. Verify state, the bound HTTP.sys reservations, and recent System log entries.

Get-Service -Name iis
Get-WinEvent -LogName System -MaxEvents 40
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 10

Root Cause Analysis

Root causes include a corrupt applicationHost.config, port 80/443 captured by another listener, missing HTTP.sys driver registration, or WAS dependency failure after servicing.

Quick Triage

Confirm the service state and read the most recent error events before any reconfiguration attempt.

sc.exe query iis
Get-Service -Name iis | Select-Object Status,StartType
Get-EventLog -LogName System -Newest 30 | Where-Object {$_.Source -match 'iis'}

Step-by-Step Diagnosis

Inspect the System and IIS configuration logs, then check HTTP.sys bindings and verify applicationHost.config integrity.

Get-WinEvent -LogName System -MaxEvents 50 | Where-Object {$_.ProviderName -match 'iis'} | Select TimeCreated,Id,LevelDisplayName,Message
sc.exe qfailure iis
sfc /verifyonly

Solution — Primary Fix

Reset HTTP.sys reservations, restart the dependency chain WAS → W3SVC, and let IIS rebuild port bindings cleanly.

Restart-Service -Name iis -Force
Get-Service -Name iis | Select-Object Status,StartType
Get-WinEvent -LogName System -MaxEvents 20 | Where-Object {$_.ProviderName -match 'iis'}

Solution — Alternative Approaches

If config is corrupt, restore applicationHost.config from the IIS history store and reattempt service start.

sc.exe config iis start= auto
sc.exe failure iis reset= 86400 actions= restart/60000/restart/60000/run/1000
Restart-Service -Name iis -Force

Verification & Acceptance Criteria

W3SVC and WAS both report Running, sites bind without error, and the System log shows no fresh W3SVC failure events.

Get-Service -Name iis
Get-WinEvent -LogName System -MaxEvents 25 | Where-Object {$_.ProviderName -match 'iis' -and $_.LevelDisplayName -eq 'Error'}
Test-NetConnection -ComputerName localhost -Port 

Rollback Plan

Stop W3SVC, revert applicationHost.config to the previous good snapshot, and restart services to the known baseline.

Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5
wbadmin get versions
# Restore previous configuration export if available

Prevention & Hardening

Monitor IIS config changes, keep the applicationHost.config history retention high, and validate listener bindings during change windows.

Get-Service -Name iis | Export-Clixml C:/Temp/iis-baseline.xml
Get-WinEvent -LogName System -MaxEvents 50 > C:/Temp/iis-events.txt
Get-ScheduledTask | Where-Object {$_.TaskName -match 'iis'}

Related Errors & Cross-Refs

Related to event 7024 service errors and HTTP.sys event 15005 binding conflicts.

Related tutorial: View the step-by-step tutorial for Windows Server 2019.

View all Windows Server 2019 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Microsoft Learn documentation for IIS service startup, HTTP.sys reservations, and applicationHost.config recovery on Windows Server 2019.