This document describes how to setup the Serialio.com USB-to-Serial adapter with a Windows Virtual machine under Parallels.

The first step is to configure the USB device settings in Parallels.

Click on USB Controller under Resources and the Parallels Configuration Editor dialog should appear

Select both checkboxes under USB Options:
            -Device Status: Enabled
            -Connection Options: Autoconnect USB devices

Next, launch the Windows Virtual Machine.

Install the Windows drivers for the USB-to-Serial adapter. The drivers can be found here

Plug in the USB-to-Serial adapter.   Your Virtual Machine should recognize the hardware. 

You can verify that the adapter has been properly installed by checking
Control Panel > System > Hardware > Device Manager > Ports

Now you can begin using the USB-to-Serial adapter on the Windows Virtual Machine.

To purchase the USB to Serial RS-232 adaptor that works with a Windows XP VM on Parallels click here.