A recent Microsoft Windows 11 security update has caused major performance drops in Assassins Creed Shadows, slashing frame rates by up to fifty percent on high end Nvidia graphics cards. Nvidia stepped in with a quick driver fix, but gamers are still dealing with the fallout as of late November 2025.
What Happened with the Update
Microsoft rolled out the KB5066835 update in October 2025 as part of its regular security patches for Windows 11. This change aimed to boost system stability but ended up messing with how the operating system handles graphics processing.
Many players noticed their games running slower right after the install. Reports flooded online forums, with users sharing stories of sudden frame rate dips during intense scenes. The issue hit hardest in open world titles like Assassins Creed Shadows, where complex environments demand heavy GPU work.
Experts traced the problem to a bug in how Windows communicates with Nvidia hardware. This led to inefficient resource use, making even powerful setups struggle.
Impact on Assassins Creed Shadows Players
Gamers playing Assassins Creed Shadows felt the hit most. The game, set in feudal Japan with detailed stealth and combat, relies on smooth performance for immersion.
One player described dropping from steady sixty frames per second to below forty in crowded areas. This made actions like parkour and sword fights feel laggy and unresponsive.
Testing showed losses up to fifty percent on top tier cards like the RTX 5090. Even with settings turned down, the game failed to recover its former speed.
Communities on social platforms buzzed with frustration. Some delayed playing the game, waiting for a solution.
- Common symptoms included stuttering during exploration.
- Frame rates stuck at thirty to forty in high demand spots.
- Visual glitches appearing alongside the slowdowns.
Nvidias Quick Response
Nvidia acted fast, confirming the issue in mid November 2025. They released GeForce Hotfix Driver version 581.94 to address the Windows bug.
This update bypasses the problematic OS changes, restoring performance in affected games. Users who installed it reported big improvements, with frame rates jumping back to normal levels.
The fix works on Windows 11 versions 24H2 and 25H2. Nvidia advised downloading it from their official site for best results.
However, this is a temporary patch. Microsoft has not yet issued a full correction, leaving some players reliant on Nvidias workaround.
Broader Effects on Gaming
The problem extended beyond Assassins Creed Shadows. Other titles like Digital Combat Simulator also saw slowdowns after the update.
This highlights ongoing challenges in PC gaming, where software updates can disrupt hardware harmony. Similar issues popped up in past Windows releases, affecting games like Cyberpunk 2077.
Industry watchers point to the need for better testing between Microsoft and hardware makers. Gamers now check update notes more carefully before installing.
| Game Affected | Reported FPS Drop | Hardware Impacted |
|---|---|---|
| Assassins Creed Shadows | Up to 50% | Nvidia RTX series |
| Digital Combat Simulator | 30-40% | High-end GPUs |
| Other Windows 11 games | Variable, up to 33% | Systems post-October update |
What Gamers Can Do Now
If you face these issues, start by updating your Nvidia drivers to the hotfix version. Restart your PC after installation to ensure changes take effect.
Check for any pending Windows updates, though Microsoft has not fixed this yet. Some users rolled back the KB5066835 update, but that risks security gaps.
Tweak in game settings like disabling variable rate shading, which has helped in tests. Monitor your systems performance with tools like MSI Afterburner.
For long term stability, consider joining beta programs from Nvidia or Microsoft to spot problems early.
Looking Ahead
Microsoft is likely working on a permanent solution, given the widespread complaints. Past patterns show they address such bugs in monthly patches.
This event reminds us how interconnected PC ecosystems are. A single update can ripple through gaming experiences worldwide.
Share your thoughts in the comments below. Have you hit this bug? Did the Nvidia fix work for you? Let us know and spread the word to help other gamers.
