Some USB Devices, such as the U3 models by Sandisk, use more than one drive letter when connecting to a machine. If the APM does not recognize the images on the drive, it may mean that a few modifications may need to be made to the kiosk configuration to get it to recognize the images on the drive.
Next, you'll need to make the necessary drive letter assignment changes for the USB drives. To start, do the following:
You should have a section that looks like the following 4 lines once it opens:
<device media_type="USB Device" ejectable="false" class="1" alert_if_missing="false" system_id="X" type="0" name="USB Device 1" enabled="true"/>
<device media_type="USB Device" ejectable="true" class="1" alert_if_missing="false" system_id="M" type="0" name="USB Device 2" enabled="true"/>
<device media_type="USB Device" ejectable="true" class="1" alert_if_missing="false" system_id="N" type="0" name="USB Device 3" enabled="true"/>
<device media_type="Harddrive" ejectable="false" class="1" alert_if_missing="false" system_id="X" type="0" name="Hard drive 1" enabled="false"/>
In this example, if you insert a the USB drive and Windows assigns letters L and M, set USB Device 1 to "L" and USB Device 2 to "M". In all cases, USB Device 1 should also be the same drive letter assigned if you insert a non-U3 USB drive (since Windows assigns the next available letter in the sequence).
Also make sure enabled is set to "true" for both of them. Set enabled for Hard drive 1 to "false".