→ Applies to: SynetoOS 6.x and above

CAUSE

The installer compares version numbers across two different virtio-win numbering tracks that aren't directly comparable, so it incorrectly treats the older 1.9.x baseline as newer than the 0.1.3xx build.

Symptom

When upgrading the guest tools on a Windows VM from the default baseline (virtio-win 1.9.x) directly to a much newer build (virtio-win 0.1.3xx), the installer fails with the following error: “A newer version of Virtio-win-driver-installer is already installed”.

Solution

Step 1. Download the VirtIO Driver recommended for your OS version and extract it ("VirtIO Library Download")

Step 2. Connect the downloaded ISO to the VM ("How to Connect a CD/DVD Drive to a VM in SynetoOS 6.0")

Step 3. Connect to the VM, open PowerShell, then check the Current Drivers Versions

Get-CimInstance Win32_PnPSignedDriver | Where-Object {$_.DeviceName -like "*Red Hat*" -or $_.DeviceName -like "*VirtIO*"} | Select-Object DeviceName, DriverVersion, DriverDate | Sort-Object DeviceName

EXAMPLE OUTPUT

DeviceName                                  DriverVersion       DriverDate
Red Hat VirtIO Ethernet Adapter             100.101.104.28500   7/8/2025 5:00:00 PM
Red Hat VirtIO SCSI pass-through controller 100.101.104.28500   7/8/2025 5:00:00 PM
VirtIO Balloon Driver                       100.101.104.28500   7/8/2025 5:00:00 PM
VirtIO Serial Driver                        100.101.104.28500   7/8/2025 5:00:00 PM

Step 4. Identify the CD-ROM Drive Letter

For this example the drive letter “E:”

Step 5. Upgrade the Drivers (replace <CD-ROM_drive_letter> with the CD-ROM drive letter and <OS_version> with the OS version)

pnputil /add-driver <CD-ROM_drive_letter>\vioscsi\<OS_version>\amd64\vioscsi.inf /install
pnputil /add-driver <CD-ROM_drive_letter>\viostor\<OS_version>\amd64\viostor.inf /install
pnputil /add-driver <CD-ROM_drive_letter>\NetKVM\<OS_version>\amd64\netkvm.inf /install
pnputil /add-driver <CD-ROM_drive_letter>\Balloon\<OS_version>\amd64\balloon.inf /install
pnputil /add-driver <CD-ROM_drive_letter>\viorng\<OS_version>\amd64\viorng.inf /install
pnputil /add-driver <CD-ROM_drive_letter>\vioserial\<OS_version>\amd64\vioser.inf /install
pnputil /add-driver <CD-ROM_drive_letter>\viosock\<OS_version>\amd64\viosock.inf /install
pnputil /add-driver <CD-ROM_drive_letter>\viogpudo\<OS_version>\amd64\viogpudo.inf /install

EXAMPLE

pnputil /add-driver E:\vioscsi\2k25\amd64\vioscsi.inf /install
pnputil /add-driver E:\viostor\2k25\amd64\viostor.inf /install
pnputil /add-driver E:\NetKVM\2k25\amd64\netkvm.inf /install
pnputil /add-driver E:\Balloon\2k25\amd64\balloon.inf /install
pnputil /add-driver E:\viorng\2k25\amd64\viorng.inf /install
pnputil /add-driver E:\vioserial\2k25\amd64\vioser.inf /install
pnputil /add-driver E:\viosock\2k25\amd64\viosock.inf /install
pnputil /add-driver E:\viogpudo\2k25\amd64\viogpudo.inf /install

Step 6. Reboot the VM

Step 7. Connect to the VM, open PowerShell, then verify the drivers were updated

Get-CimInstance Win32_PnPSignedDriver | Where-Object {$_.DeviceName -like "*Red Hat*" -or $_.DeviceName -like "*VirtIO*"} | Select-Object DeviceName, DriverVersion, DriverDate | Sort-Object DeviceName

EXAMPLE OUTPUT

DeviceName                                  DriverVersion       DriverDate
Red Hat VirtIO Ethernet Adapter             100.103.104.30200   7/21/2026 5:00:00 PM
Red Hat VirtIO SCSI pass-through controller 100.103.104.30200   7/21/2026 5:00:00 PM
VirtIO Balloon Driver                       100.103.104.30200   7/21/2026 5:00:00 PM
VirtIO Serial Driver                        100.103.104.30200   7/21/2026 5:00:00 PM

NOTE
If DriverVersion and DriverDate are unchanged, the drivers were not actually updated, re-check the mounted ISO path and drive letter, and confirm each pnputil command completed without error.