I had a similar problem when I got my VEC Foot Pedal.
Run Express Scribe, Select Settings, Select Control.
Select the check box by "Use Foot Pedal Playback Control"
Select "VEC Pedals USB" from the Port dropdown and then "3 Pedals" from the No. dropdown.
Select the "Foot Pedal Control Setup Wizard"
It will ask you to select the Rewind Pedal, then the Fast Forward Pedal then the Play pedal.
It should work after that.