Microsoft has made improvements in Windows 11 to 21h2, one of them being Virtualization-Based Security (VBS), also known as Core Isolation. As the name suggests, VBS is designed to provide “additional protection against malware and other attacks” by isolating computer processes from operating systems and devices.
However, as a result, tuning tools such as Intel’s Extreme Tuning Utility (XTU) and MSI’s Afterburner no longer work properly. For example, XTU may display “overclocking disabled” on a system that is fully capable of overclocking. It appears that this issue is caused by VBS or core isolation on Windows 11 preventing this software from accessing various registers, such as the overclocking mailbox area (MSR 150h), Which are important for things like overclocking, over- or under-voltage chips. The problem persists even when the user tries to change the settings from the BIOS. These issues have been 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. However, on Windows 11, at least initially, VBS is turned on by default on clean Windows 11 installations. Microsoft may have turned it off in a later build, but a new report suggests that a recent Windows 11 update has re-enabled the feature again by default.
VBS has been a hot topic since it was first enabled in Windows 11. There have been reports of poor gaming performance even with the feature enabled on fully supported systems.