I recently purchased an ASUS Maximus Motherboard and the chipset on the motherboard is a z68. Currently right now I have p67 chipset. I tried to startup windows and it started fine but my keyboard and mouse won't pick up in Windows. I have tried all USB ports including the PS2 port. The mouse and keyboard both work in the Bios tho
Try putting in the windows installation disk, that should load windows default drivers and then click repair and hopefully it should get rid of the old chipset drivers. If not, then try booting into safemode in windows and manually delete all drivers related to the chipset and when you reboot windows should download all the new drivers, or you can put them in yourself.