Information
Ensure that no device is connected to a virtual machine if it is not required. For example, floppy, serial and parallel ports are rarely used for virtual machines in a datacenter environment, and CD/DVD drives are usually connected only temporarily during software installation.
Solution
From the vSphere Web Client right-click the Virtual Machine and go to Edit Settings. Select the USB controller and click the circle-x to remove then OK.
or
From a PowerCLI command prompt while connected to the ESXi host or vCenter server, run the following command:
Get-VM 'VM Name' | Get-USBDevice | Remove-USBDevice
Note: This will not remove the USB controller just any connected devices.