gotta play safe imho
not sure if the tascam has got driver written for win 7 or usb class compliant interface. If theres a need to install the driver inorder to work, then tascam will have to provide the win 7 driver, if not the interface might not be recognised within the comp
if usb class compliant, most likely its just plug an play, with the name of the interface shown in the audio preference page of your daw.
Usually for product drivers, if the manufacturer never state the compatibility or having drivers for their product with particular os, its better to check with them to confirm.
anyway, to play safe, maybe can drop them a mail or check out tascam forum(if any) to see if theres driver for it or usb class compliant one.