Problem with multiple monitors

[yann458]

Hello,

I'm using VirtualBox 7.1.8 on Linux Debian 12.
Guest OS : Windows 10
Host OS : Linux Debian 12 x64
Since version 7.1.x, I've been experiencing an issue with Windows guest machines configured with two monitors:
the second screen becomes unavailable, even though the latest Guest Additions are installed correctly.
The number monitors is fixed to 2 with 128 Mb memory.

Symptoms:

In the menu View → Virtual Screen 2, the "Enabled" option is grayed out.

I tried uninstalling and reinstalling the Guest Additions, but the issue persists.

When I perform a System Restore in Windows, the second screen becomes available again.

Assumption:

The issue seems to be related to the VirtualBox Guest Additions.
Question:

If the problem happens again,
which Windows registry keys should I delete after uninstalling the Guest Additions, to ensure a clean reinstall?


Thanks in advance for your help!