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 Client select the Virtual Machine right click and go to Edit Settings. Select the USB controller and click 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.