USB support for ESX/ESXi 4.1

ESX 4.1 supports USB device passthrough from an ESX or ESXi to a virtual machine.
This article provides information about USB device passthrough
requirements and limitations, as well as steps to add a USB controller
and a USB device.
Requirements
USB device passthrough requires:

• Virtual hardware version 7 or higher
• A USB Arbitrator
• A USB controller
• A USB device or device hub

Limitations
The USB Controller has these limitations:

• USB controller hardware and modules that support USB 2.0 and USB 1.1 devices must be present on the host.
• You can add only one virtual USB controller to each virtual machine.
• The USB arbitrator can monitor a maximum of 15 USB controllers.
  If your system includes an additional number of controllers and you
  connect USB devices to these controllers, the devices are not available
  to the virtual machine.
• You must add the USB controller to the virtual machine before you can add a USB device.
• You must remove all USB devices before you remove the controller.

USB devices have these limitations:

• You can add multiple USB devices to a virtual machine that
  resides on an ESX/ESXi host to which the devices are physically
  attached.
• A USB device is available to only one virtual machine at a time.
• You can add up to 20 USB devices to a virtual machine.
• Unsupported USB devices may not interact as expected with other ESX/ESXi features. For a list of supported USB devices.
• Before you hot add memory, CPU, or PCI devices, you must remove
  any USB devices. Hot adding these resources disconnects USB devices,
  which may result in data loss.
• When you suspend and resume a virtual machine, USB devices behave as if they have been disconnected, then reconnected.
• The virtual machine cannot boot from the attached USB device.

Adding a USB controller and a USB device
To add a USB controller in a virtual machine running operating system:

1. Right-click the virtual machine and click Edit Settings.
2. Click Add.
3. Select USB Controller and click Next.
4. Click OK.
5. Go to Control Panel > Administrative Tools > Disk Management.
6. Right-click the USB disk and assign a letter.

To add a USB device:

1. Right-click the virtual machine and click Edit Settings.
2. Click Add.
3. Select USB Device and click Next.

Thats all