Is this Photoshop 4 or Photoshop CS 4 or Photoshop Elements 4, etc. Please let us know what OS you are running. XP 64-bit, Vista-64-bit, Windows 7 64-bit or even Mac OS X.7 64-bit.
Old software will not be provided with new drivers for compatibility with new hardware. It is not unusual for new hardware to require new software and new software to require new hardware, but sometimes you get luck!