PS Driver Microsoft Certified. 64 bit PostScript print driver for the Phaser 3600. Supports Windows Server 2003/2008, XP, and Vista 64 bit Operating Systems. Microsoft WHQL Certified. This driver is ONLY for use with Firmware versions prior to v1.70.02.40. For firmware version 1.70.02.40 and newer, use drivers dated 6/30/09 or later.