Purpose of this script

• make Windows load the VirtIO SCSI pass-through driver on boot without reboot or external programs

Prerequisites

• VirtIO SCSI driver (vioscsi) must be installed OR path to the INF-File must be given as argument to the script
• Windows 7/8 or Windows Server 2008 or newer versions

Remarks

• On Windows before Windows Server 2022 and Windows 10 2004 the software device created by the script will not be removed automatically, but this can be done via device manager. It can also be left there, no harm in that.
• You should have a backup of your system.
• This script was tested only
  • on Windows Server 2025 Standard Edition (24H2)
  • on Windows Server 2022 Datacenter Edition (21H2)
  • with virtio drivers version .266, .271, .285
• nearly all code in here was written by AI

How to use either

• install the vioscsi.inf before OR
• tell the script to do it by -InfPath parameter OR
• use virtio-win-guest-tools.exe /S to install it depending on the set security policy it might be required to run the script via PowerShell /ExecutionPolicy Bypass /File [-InfPath <path-to-vioscsi.inf>]

How does the script work?

• install the vioscsi driver, if requested
• create a software based device via Win32-API
• add some registry settings
• use pnputil to install the driver for this device
• use pnputil to remove the device

The driver-to-device assignment marks the driver for being loaded on boot. Now the Windows is ready for migration to a VirtIO based SCSI disk.