Microsoft has released KB5101684, an optional preview update for Windows 11 24H2 (build 26100.8973) and 25H2 (build 26200.8973). It showed up as part of the “D-week” rollout — the batch of optional, non-security previews Microsoft ships in the last week of the month, separate from the regular Patch Tuesday security updates.
Because it’s optional, KB5101684 won’t install itself. You’ll need to either grab it manually through Windows Update, or download the standalone package if it isn’t showing up on your PC yet. Below I’ll walk through what’s actually new, how to install it the normal way, and how to install it manually on a PC that Microsoft doesn’t officially support — plus what to do if Windows Update is broken and won’t cooperate at all.
Why KB5101684 Doesn’t Install Automatically
Optional preview updates are how Microsoft lets people test upcoming fixes before they get folded into next month’s mandatory security update. That means:
- It won’t download on its own unless you’ve turned on “Get the latest updates as soon as they’re available.”
- You need to go into Settings → Windows Update and manually click Download & install.
- If your PC is stable and you don’t care about early access to these fixes, you can safely skip it — everything here will arrive automatically next month anyway.
What’s Actually New in KB5101684
I tested the update on two separate machines rather than just reading the changelog, and here’s what I found.
File Explorer File Size Fix — Does It Actually Work?
Microsoft’s changelog says file sizes in File Explorer’s Details view now display in the correct units (KB, MB, GB) instead of everything being shown in KB, and that the numbers themselves should be more accurate.
I tested this directly: on my first PC, a file showed as 20 MB in Details view when the real size was 19.6 MB. After installing KB5101684 and checking again with a different file, the size shown still didn’t match the actual file properties. So while Microsoft claims this is fixed, I wasn’t able to confirm it on either of my test machines. If you install it and check your own files, let me know what you see.
Windows Search Improvements
Search is noticeably better at handling typos and partial file or app names. I also noticed a new option under Search Settings to add extra drives to be indexed (for example, adding a D: drive alongside C:), which may or may not be new depending on your build — worth checking if you search across multiple drives.
Start Menu
Microsoft describes general reliability and speed improvements to the Start menu. Nothing dramatic to point at visually, but it does feel snappier in daily use.
Also Included (Not Tested Hands-On in This Guide)
According to Microsoft’s official release notes, KB5101684 also includes Windows Hello improvements, new touchpad gesture controls, and additional reliability fixes elsewhere in the OS. I didn’t test these directly, so I won’t claim results either way — check the official Microsoft support page (linked below) for the full list.
How to Install KB5101684 Through Windows Update (Supported PCs)
- Open Settings → Windows Update.
- If you see KB5101684 listed, click Download & install.
- If your PC health check shows it meets Windows 11’s requirements, this should complete without any extra steps.
- Restart when prompted.
- To confirm it installed, go to Settings → Windows Update → Update history and check that “2026-07 Preview Update (KB5101684)” appears at the top.
How to Install KB5101684 Manually (For Any PC, Including Unsupported Ones)
If the update isn’t showing up yet, or Windows Update fails to download or install it, you can grab the standalone package directly from the Microsoft Update Catalog.
Step 1 — Check your Windows version
Go to Settings → System → About → Windows specifications and note whether you’re on:
- Windows 11 24H2, or
- Windows 11 25H2
Step 2 — Check your processor architecture
Most PCs are x64. ARM-based devices need the ARM64 package instead. If you’re not sure, About will tell you your system type.
Step 3 — Download the correct package
Head to the Microsoft Update Catalog and search for KB5101684. You’ll see multiple entries — make sure you pick the one matching your exact Windows version (24H2 or 25H2) and processor type (x64 or ARM64). Downloading the wrong one will throw an installation error, so double-check before you download the ~4.7 GB file.
Step 4 — Install the .msu file
Double-click the downloaded standalone update package and let it run. Depending on your PC, this can take a few minutes.
Step 5 — Restart
Once installation completes, restart your PC to finish applying the update.
This same process works on unsupported PCs. I tested it on a machine that fails Microsoft’s official PC Health Check due to an unsupported processor, and the manual installation completed with no issues. Windows Update on an unsupported PC generally won’t offer this update automatically, so the manual method above is currently the only way to get it there.
Important Notes Before You Install
- This update is meant for PCs already running Windows 11 24H2 or 25H2. It will not upgrade Windows 10 or an older Windows 11 version to 24H2/25H2.
- Downloading the wrong package (wrong version or wrong architecture) will fail with an error — always verify your version and architecture first.
- This is a preview update, not a security patch. If you’d rather wait, these same fixes will arrive automatically in next month’s regular security update.
Fixing Windows Update When It Won’t Work at All
If Windows Update won’t show the update, keeps failing to download, or throws an error code you don’t recognize, the issue is often broken update components rather than the update itself. In the video I use a free portable tool that:
- Clears the Windows Update delivery files
- Resets key system folders used by Windows Update
- Clears temporary files
- Resets the Windows hosts file
- Re-enables Windows Update settings and services
- Disables software that may be blocking updates
Running this fixed the update process in my testing, though results can vary depending on what’s actually broken on your system. The tool and download link are available on the website — see the link section below.
Links
- Microsoft Update Catalog: https://www.catalog.update.microsoft.com/home.aspx
- Official KB5101684 release notes (Microsoft Support): https://www.catalog.update.microsoft.com/Search.aspx?q=KB5101684
- Windows Update Fixer (portable tool): https://github.com/Great-Software-Company/WindowsUpdateFixer
All links mentioned in the video are available above and on the accompanying YouTube video.
What’s Next
The next guide will cover the Windows 11 26H2 preview — yes, already in preview, even though the stable 26H2 release itself hasn’t shipped yet.
Did KB5101684 install successfully on your PC? Was your file size display actually fixed? Let me know in the comments — and mention whether your PC is officially supported or unsupported, I’m curious how many readers are running this on unsupported hardware.
