When working with IIS 7.5, you'll notice log files are stored in folders named W3SVC followed by a number (e.g., W3SVC1, W3SVC2) under C:\inetpub\logs\LogFiles. Unlike IIS 6.0 which displayed this mapping clearly, IIS 7.5 requires a different approach to match websites with their corresponding W3SVC IDs.

The most efficient way is to use IIS's built-in command line tool:

%windir%\system32\inetsrv\appcmd.exe list site

This will output all sites with their IDs in format:

SITE "Default Web Site" (id:1,bindings:http/*:80:,state:Started)
SITE "Marketing Site" (id:3,bindings:http/*:8080:,state:Started)

The id value directly corresponds to the W3SVC folder number.

For those preferring PowerShell, try this script:

Import-Module WebAdministration
Get-ChildItem IIS:\Sites | Select-Object Name, ID

Output example:

Name            ID
----            --
Default Web Site 1
API Services     2
Blog             3

If you need this in an application, use ServerManager API:

using Microsoft.Web.Administration;

var serverManager = new ServerManager();
foreach (var site in serverManager.Sites)
{
    Console.WriteLine($"Site: {site.Name}, ID: {site.Id}");
}

Once you have the ID, you can verify the corresponding log folder contains data for your site:

dir C:\inetpub\logs\LogFiles\W3SVC3\*.log

Check the log entries match your site's domain or IP in the cs-host field.

• Don't confuse Application Pool IDs with Site IDs
• Recycled sites maintain their original W3SVC ID
• The ID remains consistent even if you stop/start the site

---

In IIS 7.5, website logs are stored in individual folders named W3SVC[ID] under C:\inetpub\logs\LogFiles. Each numeric ID corresponds to a specific website in IIS, but this mapping isn't directly visible in the IIS Manager interface.

The most reliable way to find the mapping is through the command line:

C:\Windows\System32\inetsrv\appcmd.exe list site /text:site.id

This will output all sites with their corresponding IDs. For more detailed information including site names:

C:\Windows\System32\inetsrv\appcmd.exe list site

Example output:

SITE "Default Web Site" (id:1, bindings:http/*:80:, state:Started)
SITE "Marketing Site" (id:3, bindings:http/*:8080:, state:Started)

For servers with PowerShell available, you can use:

Import-Module WebAdministration
Get-ChildItem IIS:\Sites | Select-Object Name, ID

Or alternatively:

Get-Website | Format-Table Name, ID, State, PhysicalPath -AutoSize

The mappings are also stored in the Windows Registry:

reg query "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Perflib\009" /v Counter

Note that this method shows performance counters and requires parsing to find the relevant W3SVC entries.

Imagine you have a website called "E-Commerce Platform" showing 404 errors. Here's how you'd find its logs:

1. Run: appcmd list site "E-Commerce Platform" /text:site.id
2. If it returns "4", navigate to W3SVC4 folder
3. Use PowerShell to parse recent errors:

   Select-String -Path "C:\inetpub\logs\LogFiles\W3SVC4\*.log" -Pattern "404"
   

For frequent log checking, consider creating a batch script:

@echo off
set siteName="Your Site Name"
for /f "tokens=3 delims= " %%i in ('appcmd list site %siteName% ^| find "id:"') do set siteID=%%i
echo Logs for %siteName% are in W3SVC%siteID%
pause

• Site IDs persist across IIS restarts but may change if sites are deleted and recreated
• Always use elevated command prompt (Run as Administrator)
• For clustered environments, IDs may differ between servers