Windows Command #50 – sc showsid (Windows OS)

2026-10-18

Windows Command #50 – sc showsid (Windows OS)

Windows Command #50 explains sc.exe showsid, a read-only command that calculates and displays the Windows service security identifier (SID) associated with a service name. Service SIDs help administrators assign permissions to individual services rather than to every process using a shared account.

What Is a Service SID?

A security identifier uniquely identifies a security principal in Windows. A service SID begins with S-1-5-80 and is derived deterministically from the service name. Windows can include a service SID in its process access token when configured for service isolation. The command showsid displays the derived identifier; it does not enable service isolation or change access permissions.

Run the Command

sc.exe showsid wuauserv

This example requests the SID for the Windows Update service. Use the service’s short name, not necessarily its friendly display name. The output includes the name and a long numeric SID string.

Compare SID Type

sc.exe qsidtype wuauserv

The companion qsidtype command reports whether the service’s SID type is NONE, UNRESTRICTED, or RESTRICTED. A service name can have a derived SID even when the corresponding service is not installed or is not configured to use that SID in its token. This is why showsid and qsidtype answer different questions.

Find a Service’s Short Name

sc.exe getkeyname "Windows Update"

The Service Control Manager can translate a friendly display name into the service name used by showsid. You can also inspect services through the Windows Services console.

When This Command Helps

Administrators use service SIDs when reviewing service-specific file or registry access control lists (ACLs), diagnosing permission failures, or planning service isolation. Avoid changing ACLs or service SID types on production machines without a tested change plan.

Knowledge Check

1. What does showsid display? 2. Does it change service configuration? 3. What is the difference between showsid and qsidtype? 4. Must the named service exist for Windows to derive its SID?

Answers

1. A service name’s derived SID. 2. No. 3. One displays the SID string; the other reports its configured SID type. 4. No.