If you view it in Windows explorer, it will appear as another drive, and you can browse it just as with any other drive.
I think you misunderstand me. In Windows Explorer, it shows up under 'Hard Disks' and not 'Devices with Removable Storage'. The program, Pe2USB, seems to require that the drive be recognised as a 'Device with Removable Storage'.
Of course if you know how to make a USB disk bootable using some other method, that would be fine as well. When I select it in the BIOS boot menu, it waits for a few seconds and prints out "Remove all drives and press any key to restart. . .", or something to that effect.