Windows 10 KB5040525 update patches a slew of WDAC problems, fixes Windows Backup, and addresses many more issues

It is the time of the month when Microsoft releases preview versions of updates for Windows, and with the KB5040525 update the company has a large number of fixes that will be welcomed by Windows 10 users.

Among the biggest improvements are fixes for various issues with Windows Defender Application Control. As well as addressing a troublesome memory leak, Microsoft has also taken steps to prevent stop errors caused by certain policies. Elsewhere there are WPA3 fixes, a problem with Windows Backup has been patched, and a DHCP Option 235 gremlin has been thwacked.

See also:

• Microsoft brings new archive format support, Copilot improvements and new emoji to Windows 11 with the KB5040442 update
• Intel finally determines cause of processor instability issues and has a patch in the pipeline
• Microsoft warns Windows 11 users of forced upgrades due to impending end of service for older versions

Although the KB5040525 update is a non-security update -- as is normal for preview updates -- it remains an important one. Anyone who is reliant on Windows Backup will welcome the fix for failed backups that has been introduced. Microsoft explains that the problem occurs when a device has an Extensible Firmware Interface (EFI) system partition (ESP).

There are no fewer than three significant fixes for Windows Defender Application Control (WDAC), namely:

• This update prevents a stop error that occurs when you apply more than 32 policies.
• A memory leak occurs that might exhaust system memory as time goes by. This issue occurs when you provision a device.
• When you apply WDAC Application ID policies, some apps might fail.

The update addresses a known issue with DHCP Option 235, with Microsoft saying:

Some Windows devices use this option to find Microsoft Connected Cache (MCC) nodes in their network. But you might not be able to use these nodes when you find them. Instead, these devices download updates and apps from the public internet. Because of this, download traffic increases.

There are full details about the KB5040525 update here. If you want to install the update, you can check for optional updates in Windows Update, or use the Microsoft Update Catalog website.