The Update BureauPatch Tuesday is the second Tuesday of each month, when Microsoft releases its monthly security updates for Windows and other products. The calendar lists the next dates.
Why a fixed day
A fixed day lets companies plan testing and installation, and lets everyone expect when updates come.
What arrives that day
For each Windows version, one cumulative update: it includes all the previous fixes, so installing the latest one is enough even if you skipped a month.
Updates outside Patch Tuesday
- Optional previews, usually in the fourth week: the next month's fixes, early and optional. More about previews.
- Out-of-band updates: released on any day when a problem can't wait, like a flaw attackers are already using, or a serious bug caused by a previous update.
What to do
Let Windows install the Patch Tuesday update. Check its page here if you want to know what it changes and whether there are known issues.
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