Yes, for a small pilot group. Microsoft releases an optional non-security preview update in the fourth week of each month so admins can validate content early, before it ships in the next monthly security update. Testing it on a few representative devices gives you weeks of warning about problems.
What the preview update is
Microsoft's release cycle documentation describes it as an optional, cumulative, non-security preview release. It is typically released in the fourth week of the month, and offered only to the most recent supported versions of Windows. It is meant to give IT admins an opportunity for early validation of content before the monthly security update.
Names you will see for it include D week releases (the fourth week), preview updates, preview CU and LCU preview. New features might first appear in the preview and then ship in the following month's security update.
You can get it through Windows Update by checking for updates in settings, through the Windows Insider Program for Business, or through the Microsoft Update Catalog.
Why bother
The monthly security update is cumulative and includes non-security content from the previous month's preview. If something in that content breaks a line of business application, you would otherwise find out during the Patch Tuesday rollout, when time is short. The preview moves the discovery earlier.
| Approach | When you find a problem | Cost |
|---|---|---|
| Skip the preview | During the Patch Tuesday rollout | Pressure, possible delay of a security fix |
| Test the preview on a pilot ring | About two weeks before Patch Tuesday | A few machines and an hour of testing time |
A light test plan
- Pick a pilot ring: 5 to 20 machines covering your main hardware models, key applications and one or two remote workers. Include an IT team member who will report issues the same day.
- Install the preview in the fourth week.
- Run a fixed checklist: sign-in, VPN, printing, the three most used business applications, backup agent, endpoint tools and anything that has broken before.
- Collect results in one place. A simple shared table is enough.
- Decide by the following Monday: ready, ready with known issues, or hold.
- Share the decision with the team that will deploy on Patch Tuesday.
Stop rules
Decide in advance what blocks a rollout. For example, a failure of sign-in, VPN or the main finance application is a stop. A cosmetic issue is not. Having the rule on paper means nobody argues it under pressure.
What not to do
Do not deploy the preview broadly. It is optional for a reason, and your production fleet will get the same content in the security update. Do not treat a clean preview as proof that Patch Tuesday is safe either, because the security update adds new fixes that were not in the preview. Treat it as an early signal, then still pilot on Patch Tuesday. Our Patch Tuesday explainer has a weekly routine for that step.
Document the result
Record the preview version tested, the ring, the checklist results and the decision. If a vendor update later causes trouble, this record shows you did due diligence and gives you a baseline for comparison.
Try it yourself
Click through it at your own pace, or open it full screen.
See how a gate checks a change before it merges, which is the same idea as testing a preview ring before the wide rollout.
Safeguard offers policies, gates and guardrails for code changes, plus compliance evidence automation to keep your test records. Try a free scan.
Quick check
Is the preview update a security update?
Microsoft describes it as an optional non-security preview. The security fixes ship in the monthly security update.
How many machines should be in the pilot ring?
There is no fixed rule. Aim for a small group that covers your hardware and key applications, often 5 to 20 devices.
Sources
- Microsoft Learn, Update release cycle for Windows clients
Last reviewed: 19 October 2026.
