A: Prior to vSphere v4.0 Update 1, the VMware Paravirtual SCSI (PVSCSI) driver didn't support booting Windows guests. Windows guests requiring the PVSCSI driver were recommended to create separate boot and data drives, with the PVSCSI driver operating exclusively for the data drive.

The PVSCSI driver supports booting Windows guests with the release of vSphere v4.0 Update 1. This driver must be installed into the Windows guest from the VMware Tools or its VMware-supplied floppy disk image. Floppy disk images with the driver can be found in the /vmimages/floppies directory on an ESX/ESXi host.

Existing OSs can be migrated to the PVSCSI driver using the following process:

  1. Upgrade the VMware Tools to the current version or install the PVSCSI driver from its floppy disk image.
  2. Add a new virtual hard disk of any size to the VM. Attach it to SCSI node 1:x.
  3. Change the type of the new virtual hard disk to VMware Paravirtual.
  4. Power on the VM, login, and allow it to complete any driver installations. Then, power down the VM.
  5. Remove the just-created virtual hard disk from the VM and change the type of the original SCSI controller to VMware Paravirtual.
  6. Finally, power back on the VM and remove the device drivers for the old SCSI adapter in Device Manager. These device drivers may be hidden. To expose the hidden device drivers, enter the following two commands to start Device Manager.

    set devmgr_show_nonpresent_devices=1
    start devmgmt.msc

    Once it's started, select View, Show Hidden Devices to expose and remove the hidden drivers.