PST is pleased to introduce a digitally signed Port Driver capable of being installed on Windows XP and Windows Vista 32-bit and 64-bit systems. The installation of the Port Driver will occur during installation of E-Prime and will not require the "continue anyway" style prompts necessary by drivers with no digital signature. PST has verified that the Port Driver will provide millisecond accuracy on XP/Vista 32/64-Bit environments. Use of the Port Driver will have no script or design changes (i.e. WritePort, PortDevice, etc) remain the same.