Windows 7 Drivers available from Lexmark Download
Lexmark 4200 Driver: Download
You can use this driver for both models of Lexmark 4200 series printers.
Lexmark 4200 Series Printers: X4250, X4270
This driver supports Microsoft Windows 7, Vista (32 bit and 64 bit versions) & XP (32 bit). This is a free driver installer package from Lexmark for the all-in-one Lexmark X4270 amd x4250 printer model.