ASIO DRIVERS NOT ON LIST CUBASE 4

Having used cubase 4 with Edirol FA-66 audio capture for some years it has inexplicably dissapeared from VST ASIO seiection list… Have re stalled FA-66 driver, reloaded cubase from scratch and even downloaded driver ASIO4ALL but still can’t see the list of available drivers on the device setup page!!! Anyone have any ideas on this one please??
I’m running windows 8.1 32bit
Many thanks
Phil