Upgrading the hardware version of Windows virtual machines may require driver updates

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:
After upgrading a Windows virtual machine to hardware version 7 on an ESXi/ESX 4.0 host, you may experience these symptoms:

• The Flexible NIC only has 10Mbps speed.
• The Flexible NIC incorrectly uses the AMD PCNET family PCI Ethernet adapter (pcnetpci5.sys) driver.

Environment

VMware ESX 4.0.x
VMware ESXi 4.0.x Installable
VMware ESXi 4.0.x Embedded

Resolution

The correct driver is the VMware Accelerated AMD PCnet Adapter (vmxnet.sys) driver, which allows 1Gbps speed.

To choose the correct driver, manually update the driver that the Flexible NIC uses by pointing to C:\Program Files\VMware\VMware Tools\Drivers\vmware-nic.inf from the virtual machine Windows guest operating system.