Checking, installing, and confirming Windows updates without a GUI

Goal

Check, install, and confirm operating-system updates on a Windows Server host that has no desktop, and know beforehand whether it is already waiting on a reboot.

Prerequisites

Administrator rights; either direct Windows Update access or a configured WSUS server; this article treats WSUS as the primary managed-patching path — third-party patch-management tools exist but are not covered here.

Steps

1. On Server Core, sconfig's update page sets the policy directly: Automatic checks and installs on a daily schedule, Download only (the documented default) downloads and notifies without installing, and Manual does neither automatically.
2. In a managed environment, updates are normally approved and delivered through Windows Server Update Services (WSUS) rather than each server reaching Windows Update directly; WSUS policy (approval groups, deadlines, and client targeting) is generally set through Group Policy pointing clients at the WSUS server.
3. Before installing anything, check whether the host is already waiting on a reboot from an earlier action, so you don't stack changes on an inconsistent state. A concrete, checkable example: reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager" /v PendingFileRenameOperations — if this value exists, files are already queued to be renamed at next boot. More broadly, Windows' own Microsoft.Windows/RebootPending resource reports a pending reboot for several distinct reasons, including "Windows Updates requiring restart," "Component-Based Servicing operations," "Pending file rename operations," "Computer rename pending," and "Domain join operations pending" — treat any of these as a signal to schedule a maintenance window rather than install further changes immediately.
4. After installing updates, do not rely solely on Get-HotFix to confirm what is installed: it queries the Win32_QuickFixEngineering WMI class, which Microsoft's own class documentation states "returns only the updates supplied by Component Based Servicing (CBS)... Updates supplied by Microsoft Windows Installer (MSI) or the Windows update site... are not returned." Cross-check against Windows Update history or WSUS reporting for a complete picture.
5. Reboot in a controlled maintenance window rather than immediately: Restart-Computer -Force (non-interactive; no confirmation prompt to suppress).

Expected result

The pending-reboot check in step 3 returns nothing before maintenance and something concrete to point at if it does; after installation and reboot, both Get-HotFix and WSUS/Windows Update history show the newly applied updates.

Limits and test basis

Get-HotFix's CBS-only scope means an empty or short result does not prove a host is unpatched — a cumulative update delivered outside CBS would not appear there. Nothing here needs an explicit "undo": update installation is reversible only through Windows' own uninstall path (Get-HotFix plus wusa /uninstall /kb:<number> where applicable) or a restore point, not by reverting a configuration setting. Sconfig's update-mode change and the registry check both take effect immediately with no reboot of their own; only the updates being installed may require one.