Leadtek have released a new nForce WinFast K7N420DA autosetup driver version 1.07 which includes the chipset driver, audio driver, LAN driver and VGA driver.

Download WinFast nForce Autosetup Driver v1.07 Windows 2K/XP Multilanguage

Download WinFast nForce Autosetup Driver v1.07 Windows 9X/ME Multilanguage

And before I forget: There's a new BIOS for the WinFast K7N420DA (English) (2002/7/25). Sorry no version number but here's what's new: Fixes Hardware Monitor disappeared bug.