Windows 11 August 2026 Update: What's New, What's Fixed, and What to Do If Something Breaks
Microsoft's August 2026 Patch Tuesday landed on 11 August with new Windows 11 features and one of the year's biggest security patches — including a flaw already being exploited by attackers. Here's what actually changed, and what to do if your PC starts acting up after installing it.
Update — 15 August 2026
Tech press is now urging anyone who hasn't yet installed this update to do so within a few days, given the volume of fixes and the actively-exploited flaw detailed below (WindowsLatest, 14 Aug 2026). Separately, some users are reporting that Windows Security shows a false "virus protection is off" notification after installing this update, even though antivirus is actually running normally — this looks like a display bug in Windows Security Center, not a real protection failure. We've published a full explainer covering how to check you're genuinely protected and when it's worth a professional look: Windows says "turn on virus protection" but Defender is already on?
What's in the Windows 11 August 2026 update
Microsoft released the August 2026 quality update for Windows 11 on Tuesday, 11 August 2026. Which KB you receive depends on your Windows 11 version:
| Windows 11 version | Update | New build |
|---|---|---|
| 24H2 / 25H2 | KB5121003 | 26100.9168 / 26200.9168 |
| 23H2 | KB5120240 | 22631.7517 |
| 26H1 (Insider/early rollout) | KB5121000 | 28000.2704 |
You can check which version you're on via Settings > System > About. If you're not sure, or Settings won't open properly, that's often a sign your machine needs a closer look — see the troubleshooting section below.
New features worth knowing about
This is a feature-rich update alongside the security fixes. The main changes Microsoft is rolling out (gradually, via Controlled Feature Rollout, so you may not see everything immediately):
- Windows Hello Enhanced Sign-in Security (ESS) now supports external fingerprint readers, not just built-in sensors on Copilot+ PCs — useful if you use a USB fingerprint dongle on a desktop.
- AI model uninstall option — you can now remove the Image Generation AI model from Settings > System > AI Components if you don't use Copilot's on-device features.
- File Explorer now shows file sizes in proper units (KB, MB, GB) in Details view instead of always defaulting to kilobytes, plus middle-click to open folders in new tabs.
- Windows Search handles typos and short two-character queries better, and ranks Settings results more sensibly.
- Touchpad gestures — you can now customise scroll and zoom speed, and enable accelerated scrolling.
- Power & battery — display timeout, sleep/hibernate and lid-close settings now apply across all power plans, not just the active one; Energy Saver battery-percentage trigger is back.
Why this update matters: one of the year's largest security patches
Alongside the features, Microsoft fixed 400 vulnerabilities this month — 42 rated Critical (37 remote code execution, 5 elevation of privilege) — across Windows, Office, SharePoint Server, Azure, Developer Tools and Exchange. It's smaller than July's record 570-flaw update, but still a very large release by historical standards, and Microsoft has flagged that AI-assisted vulnerability discovery is likely to keep these numbers elevated going forward (BleepingComputer, 11 Aug 2026).
The flaw already being exploited
⚠ CVE-2026-68820 — actively exploited
A use-after-free vulnerability in the Windows Ancillary Function Driver for WinSock (AFD.sys) lets an attacker who already has some access to a machine elevate themselves to full SYSTEM privileges. Security firm Check Point reports this flaw was used by the North Korea-linked "Lazarus" group to deploy a kernel-mode rootkit during a job-offer-themed social-engineering attack. Microsoft has not disclosed further exploitation details. (Source: Microsoft Security Response Center advisory; reported by BleepingComputer, 11 Aug 2026, and Check Point Research.)
Two further zero-days were fixed that had already been publicly disclosed before Microsoft's patch, including CVE-2026-62832 — a Windows User Profile Service elevation-of-privilege bug matching a previously-published exploit technique nicknamed "LegacyHive." Neither of these two had confirmed active exploitation at the time of Microsoft's release, but public disclosure means the technical details were already circulating, which typically raises the risk of exploitation attempts.
For most home and small-business users, the practical takeaway is simple: these are the kinds of vulnerabilities that let malware already on a PC (for example from a phishing click) gain full control of the system — so timely installation matters more than usual this month.
Should you install it straight away?
Given the actively-exploited flaw, we'd generally recommend not delaying this one. A few sensible precautions first:
- Back up first. A quick backup of your documents and photos to an external drive or cloud storage before any major Windows update is cheap insurance.
- Check for known issues on your specific brand. Dell and HP models have both had update-related BitLocker recovery loops and blue screens this year on earlier updates — see our guide on Dell/HP BitLocker and BSOD recovery loops if that's happened to you before.
- Make sure you have enough free disk space — low storage is one of the most common causes of a stalled or failed Windows update.
- Don't interrupt the install — let the PC finish and restart on its own, even if it takes a while on the "Working on updates" screen.
What if the update causes problems on your PC?
Large monthly updates occasionally trigger issues, particularly on older or heavily customised machines, or where a manufacturer's own software (BIOS, driver-management tools) conflicts with the changes Windows makes. Problems we commonly see after big Patch Tuesday releases include:
Boot loops or "preparing automatic repair"
The PC restarts repeatedly without fully loading Windows. This can be a corrupted update installation, a driver conflict, or in some cases a sign of an ageing hard drive or SSD struggling under the extra read/write load of an update. See our guide on SSD warning signs if this keeps happening.
BitLocker asking for a recovery key
Some laptops prompt for a 48-digit BitLocker recovery key after a firmware or update-related change. If you don't have that key saved (it's usually in your Microsoft account), don't keep guessing — repeated failed attempts can lock the drive further. Our Dell/HP BitLocker loop guide covers this in detail.
Wi-Fi or Bluetooth drops out after updating
Network driver conflicts after a Windows update are common enough that we've written a dedicated guide: Windows 11 Wi-Fi/Bluetooth disconnecting.
The PC feels slower after updating
A brief slowdown for a day or so while background indexing and cleanup finish is normal. If it doesn't settle down, see our guide on diagnosing high CPU, disk or memory usage.
When it's worth bringing it in
If your PC won't get past the boot repair screen, keeps demanding a BitLocker key you don't have, or a driver reinstall hasn't fixed a Wi-Fi/performance issue, that's when it's more efficient to have it diagnosed properly rather than keep guessing. We see this pattern every Patch Tuesday across Windows laptops and desktops from all the major brands.
Local support in Carrum Downs and southeast Melbourne
If this month's update — or any Windows update — has left your laptop or desktop stuck, Macrotech Solutions diagnoses and repairs Windows PCs at our Carrum Downs workshop, with customers regularly coming in from Frankston, Cranbourne, Lyndhurst, Langwarrin, Seaford, Skye and Patterson Lakes. We check whether an issue is update-related, driver-related, or a sign of underlying hardware wear (storage, battery, motherboard) before recommending any repair.
PC stuck after the Windows update?
Bring it in for a diagnostic at our Carrum Downs workshop, or call us to talk through what's happening.
Call 03 8759 1801Frequently Asked Questions
Do I have to install the August 2026 Windows 11 update?
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Is this update different from the July 2026 update?
Macrotech Solutions is an independent computer repair specialist and is not affiliated with, endorsed by, or sponsored by Microsoft Corporation. Windows and Windows 11 are trademarks of Microsoft Corporation. Information in this article is accurate as of 15 August 2026 based on Microsoft's and independent security researchers' published advisories; always check Microsoft's Security Update Guide for the latest status.