October 2026 Windows Update: Known Problems and Fixes

October's Windows update has been out for two days. Here's what's gone wrong so far and what you can do about it.

Three things so far. One is a proper bug that's been hanging around since September, one mostly bites businesses, and one isn't a bug at all but a deadline that's just passed.

USB headsets and sound cards going silent

You install the update and your USB headset stops working. Or your USB desk speakers, or the little USB sound card dongle you bought years ago. No sound at all. The volume slider does nothing, and the sound settings are greyed out or the device has vanished from the list.

Open Device Manager and you'll see a yellow warning triangle on the audio device with the message "This device cannot start (Code 10)".

It hits anything using the older USB Audio Class 1.0 standard, which covers a lot of older and cheaper kit: USB headsets from a few years back, plug-in sound cards, some of the audio interfaces musicians use for recording, and plenty of USB speakers. Windows 10 and Windows 11 (24H2, 25H2 and 26H2) are all affected. Microsoft has confirmed it.

Microsoft did push out an emergency patch on 14 September (KB5129195), but it only fixed 8-channel and 3D surround devices. Ordinary stereo headsets are still broken. There's no full fix yet.

Try switching it to 2-channel

This has brought sound back for some people. Not everyone, but it's worth five minutes.

1. Plug the USB headset or speakers in.
2. Press the Windows key and R at the same time. Type mmsys.cpl and press Enter. The old Sound window opens.
3. On the Playback tab, click your USB device once to select it, then click Properties.
4. Go to the Advanced tab.
5. Under Default Format, open the drop-down and pick an option that starts with "2 channel" (for example "2 channel, 16 bit, 48000 Hz").
6. Click Apply, then OK.
7. Unplug the device, wait ten seconds, and plug it back in.

If your headset doesn't appear in the Playback list at all, this won't help. Skip to the next bit.

If it still won't play

Use something that doesn't go through USB audio. A headset with a normal 3.5mm headphone plug, or a Bluetooth headset, will work fine. Not ideal if you've got a work call in ten minutes and your good headset is the USB one, but it gets you through until Microsoft fixes it properly.

Remote Desktop won't connect (error 0xC000000D)

If you use Remote Desktop to get into another Windows PC, you might get turned away with error 0xC000000D and the message "The token that was passed to the function is invalid."

This only happens when the PC you're connecting to has Administrator protection switched on. Standard (non-admin) accounts are the ones locked out. Microsoft has acknowledged it.

Most home users won't have Administrator protection turned on. It's a newer Windows 11 security feature that IT departments tend to switch on across work machines. But if you went through your security settings at some point and turned on everything you could find, it could be you.

On a home PC

Do this on the PC you're trying to connect to, not the one you're connecting from.

1. Open Settings.
2. Go to Privacy & Security → Windows Security.
3. Click Device Security, then Core isolation.
4. Turn Administrator protection off.
5. Restart the PC when it asks, then try connecting again.

Turn it back on once Microsoft releases a fix.

On work PCs

If you look after machines at work, Microsoft's workaround is to turn Administrator protection off through Group Policy or Intune until the fix lands. In Group Policy it's under Computer Configuration → Windows Settings → Security Settings → Local Policies → Security Options. Set "User Account Control: Configure type of Admin Approval Mode" back to plain Admin Approval Mode. In Intune, the same setting sits in the Settings catalog under Local Policies Security Options. Push it out, restart, and Remote Desktop should come back.

Microsoft says a permanent fix is coming. No date yet.

Windows 11 24H2 has stopped getting security updates

Not a bug, but it's tied up with this month's update so it belongs here. Tuesday's patch was the last security update Windows 11 24H2 Home and Pro will ever get.

Your PC won't stop working. Nothing will pop up and lock you out. It simply won't receive any more security fixes, so next month's Patch Tuesday will pass it by, and so will every one after that.

Moving to a newer version is free and usually painless.

1. Open Settings → System → About.
2. Look at Version under Windows specifications. If it says 25H2 or 26H2, you're fine and can stop here.
3. If it says 24H2, go to Settings → Windows Update.
4. Click Check for updates. You should see an offer for 25H2 or 26H2. Click Download and install.
5. Leave it for 20 to 40 minutes, then restart when asked.

Your files and programs stay where they are. Back up anything you'd hate to lose first anyway. You almost certainly won't need it, but that's the whole point of a backup.

If no upgrade offer appears after a couple of tries, something is blocking it, or the PC doesn't meet the requirements. That's worth getting looked at. My 26H2 guide covers what you get with the newer version.

Should you still install the update?

Yes.

This month fixed over 1,400 vulnerabilities, and one of the zero-days is already being used in real attacks. It lets a downloaded file run without Windows showing its usual safety warning, which is exactly what scam emails rely on. The full rundown is in my October update post.

A silent USB headset is annoying. A PC with 1,400 known holes in it is a much bigger problem. Install the update, and if your headset goes quiet, try the 2-channel fix above. I wouldn't uninstall the update to get your sound back, either. You'd be swapping a nuisance for a real risk.

I'll add to this post if anything else turns up or Microsoft ships a proper fix. And if the update is causing you grief and you can't sort it yourself, that's what I'm here for: computer repairs in St Helens.

Mark

Mark has been fixing computers since the late '90s and went self-employed in 2008. Based in St Helens since 2013, he works evenings and weekends from his home in Laffak, doing friendly, affordable repairs for PCs, laptops, and Macs. See reviews on Google