What is a WSUS server and why install it in a business? - Windows Server - Tutorials

When you have many servers and/or client workstations in a company, it is advantageous to install a WSUS server to manage their updates centrally.

What is SUS (Software Update Services)?
What is WSUS (Windows Server Update Services)?
Why install a WSUS server?
Advantages of deploying a WSUS server

1. What is SUS (Software Update Services)?

As stated on the Microsoft website, SUS (Software Update Services) allowed system administrators to quickly manage and deploy updates for:

server operating systems: Windows 2000, Windows Server 2003
client operating systems: Windows 2000 Professional and Windows XP Professional

In other words, SUS only allows you to manage updates for Windows and Windows Server.

2. What is WSUS (Windows Server Update Services)?

WSUS (Windows Server Update Services) is the successor to SUS (Software Update Services) and allows system administrators to deploy the latest available updates for Microsoft products more quickly and reliably.

Installing updates for your various Microsoft products helps ensure the stability and security of your servers and client workstations by installing:

critical updates to fix critical issues
security updates to fix security vulnerabilities
updates to fix various problems (including stability updates)
etc.

2.1. Products supported by WSUS

WSUS (Windows Server Update Services) allows you to manage updates for all existing Microsoft products:

their server operating systems: Microsoft Server 24H2, 23H2, 22H2, 21H2, Windows Server 2019, 2016, ...
their client operating systems: Windows 11, 10, 8.1, 8, 7, ...
their Office suites: Microsoft 365, Microsoft Office 2019, 2016, ...
their email servers: Microsoft Exchange 2025, 2019, 2016, ...
their database servers and associated management tools: SQL Server 2022, 2019, 2017, ..., SQL Server Management Tools v20, v19, v18, ...
their IT asset management solutions: System Center 2022, 2019, 2016, ...
and much more.

2.2. Update classifications

When you manage updates for your Microsoft products using a WSUS server, you can choose the type of updates you want to download and deploy to your servers and/or client workstations using the different classifications available:

Update packages: as the name suggests, these are sets of updates designed to facilitate deployment. They can contain critical updates, security updates, and more. They are generally targeted at a specific product component (e.g., IIS) or security features.
Feature packs: new features distributed as updates and often included in the next version of the product.
Driver sets: a package of drivers that enables support for specific hardware.
Critical update: a patch that fixes a specific problem (a critical bug) but is not related to security.
Security update: a patch that fixes a vulnerability or security flaw found in the product.
Update: a patch that fixes a specific problem but is not a critical bug.
Definition updates: frequent updates that add definitions to the product's database.
Tool: tools or features that perform certain tasks.
Driver: automatically updates Microsoft-supported drivers on your servers and client workstations.
Service pack: automatically deploys service packs via WSUS.
Although in production, this is often managed manually for reasons of stability, compatibility with installed applications, and performance (primarily network performance).
For example: by manually downloading the service pack from the Microsoft website and then installing it from a USB drive rather than transferring it over the network as would be the case using WSUS.
Upgrades: allow you to update Windows 10 to a newer version of the same OS or to Windows 11 (for example) without relying on Microsoft Update on your servers and workstations.

As you can see, you will therefore be able to choose:

to install only important updates: critical and security updates
or to install all updates, including optional updates: such as feature packs, tools, etc.

For more information about these classifications, see the "Configure classifications and products to synchronize" page on the Microsoft website.

2.3. Update languages

When you deploy a WSUS server, you can choose the languages you want for downloading updates.
Among the supported languages, you will obviously find French and English, but note that there are currently around thirty languages available.

Therefore, you can use WSUS:

in a company located in a single location, such as a very small business or a small to medium-sized enterprise (SME).
but also in the case of a multinational corporation, to deploy updates in different countries (and therefore in multiple languages) by managing the choice of updates directly at headquarters (if desired).

3. Why install a WSUS server?

By default, each server and client workstation is configured to download updates (for Windows, Microsoft Office, etc.) from Microsoft Update.
This means that if you have many servers and/or computers in your company, downloading these updates will quickly saturate your internet and network bandwidth.
Indeed, every server and client workstation in your company will download the same file from the internet.

If a 100 MB update is released by Microsoft and you have 50 servers and/or client workstations, this means your company will download 5 GB of data over the internet instead of just 100 MB.

By deploying a WSUS server, the WSUS server will be the single server downloading all the necessary updates for all the servers and client workstations in your company.
Then, you will configure your servers and client workstations to synchronize with your WSUS server. Therefore, they will download their Microsoft updates from your WSUS server and not from the official Microsoft server (namely: Microsoft Update).

4. Advantages of deploying a WSUS server

The main advantages of deploying a WSUS server are:

reduced bandwidth usage (for both the internet and your local network), as well as reduced download times for updates across your company.
Each update will be downloaded only once by your WSUS server, not by each individual server and/or client workstation.
the ability to manage which updates are downloaded and installed on servers and client workstations.
You can approve or reject each update to avoid deploying updates that could cause problems on your servers or client workstations.
centralizing update management on the WSUS server eliminates the need to manage updates on each server and client workstation individually.
This significantly simplifies update management across your IT infrastructure and saves you considerable time on server and client maintenance.