[Bug]: The latest build (7.2.8) will not run Windows 11(Guest) unless you the number of CPUs to 1

[kberish]

Version

trunk/main

Host OS Type

macOS

Host OS name + version

Windows 11 25H2

Host Architecture

x86

Guest OS Type

Windows

Guest Architecture

x86

Guest OS name + version

Windows 11 25H2

Component

Other

What happened?

The latest build of Virtualbox (7.2.8

Win11-2026-04-29-08-43-02.log

) will not run Windows 11 (25H2) Guest unless you the number of CPUs to 1. The previous version of VirtualBox did not have this issue on my Windows 11 25H2 host.

How can we reproduce this?

To reproduce the issue, try installing Windows 11 25H2 guest with more than 1 cpu with VirtualBox 7.2.8.

Did you upload all of your necessary log files, screenshots, etc.?

• Yes, I've uploaded all pertinent files to this issue.

[kberish]

I accidently chose the host os type as mac, it should be Windows.