How Microsoft’s new Windows 11 update broke Assassin’s Creed Shadow and what you can do to fix it
According to reports, Microsoft’s Windows 11 update in October caused major disruptions for gamers playing Assassin’s Creed Shadows. Here’s what happened, and how you can fix your PC if you’re experiencing the same problem.
Let’s be honest, Windows Updates can be annoying. While you’re doing something important, your PC may decide to go into an update loop, sometimes causing you to wait up to an hour depending on your device. But it’s all for the greater good, an update will make your device smoother and fix bugs. However, as it turns out, the Windows 11 update broke Assassin’s Creed Shadow on PC.
What happened after Windows 11 update?
According to Digital Foundry, Microsoft’s October 2025 Windows 11 update, identified as KB5066835, was the root cause of the disruption in Assassin’s Creed Shadows. Following the rollout of the update, users noticed a dramatic drop in frame rates, especially on systems using Nvidia graphics cards.
The feedback from players began after many reported that their frame rates in Assassin’s Creed Shadows had dropped after installing the Windows 11 update, even on high-end hardware such as the Ryzen 7 9800X3D CPU and Nvidia RTX 5090 GPU. The report documents a case where the RTX 5090’s output dropped from 72 to just 34 frames per second at 4K DLSS quality settings after the update, highlighting the scale of the impact.
Why did Assassin’s Creed Shadows performance drop?
The situation became more clear when Nvidia published a statement saying that the October patch for Windows 11 versions 24H2 and 25H2 “may cause ‘reduced performance’ in some games.”
The exact technical cause of the bug remains unclear. Nvidia indirectly suggests that it is Microsoft’s fault by saying that the problem occurs ‘after updating to Windows 11 October 2025 KB5066835’, but the company does not directly blame Microsoft. This leaves open the possibility that either Microsoft’s Windows updates or changes to Nvidia’s drivers – or both – could be responsible for the observed performance drop.
How to Fix Windows 11 Update Problem on Assassin’s Creed Shadows
According to the report, installing Nvidia’s emergency GPU driver hotfix and re-running the benchmarks at the same in-game locations resulted in an apparent restoration of performance. This suggests that the problem was directly related to the interaction between Nvidia’s drivers and Windows Update.
Notably, while Assassin’s Creed Shadows was the most prominently affected title, there were indications that other games, such as Counter-Strike 2, also experienced frame rate increases and drops prior to the hotfix. Despite this, Nvidia has not provided a comprehensive list of affected games, instead opting for more general communication regarding “some games” being affected.
