Recent Windows 11 update apparently causing various issues due to Core Isolation (VBS)

Among the various security features that Microsoft improved with Windows 11 21H2, one of them was Virtualization-based Security (VBS), also called Core Isolation. As the name suggests, VBS is meant to provide "added protection against malware and other attacks by isolating computer processes from your operating system and device".

As a result of this however, tweaking tools like Intel's Extreme Tuning Utility (XTU), MSI's Afterburner, and others, are apparently failing to function properly. For example, XTU may show "overclocking is disabled" on a system fully capable of overclocking. The issue is seemingly being caused by VBS or Core Isolation on Windows 11 blocking access of these software to various registers like the overclocking mailbox (MSR 150h) that are essential for things like overclocking, overvolting, or undervolting chips. The problem persists even if you try to alter settings from the BIOS it seems. The problems are being reported on MSI devices but systems from other OEMs and vendors may also be affected.

While VBS is also present on Windows 10, it is not enabled by default. On Windows 11 however, VBS was on by default in clean Windows 11 installs, at least initially. A later build may have toggled it off but a new report suggests a recent Windows 11 update has once again re-enabled this feature by default.

In general, VBS has been a hot topic ever since it was first discussed about in Windows 11. There were reports of poor gaming performance with the feature enabled even on fully supported systems.

Source: 板廠沒有說的秘密 TOPPC (YouTube) via rickkuo (Reddit) , der8auer EN (YouTube)