if you unplug the printer, does the unkown device go away? i'm guessing you might have changed usb ports with it, and maybe a small item (maybe a usb port directly on the printer) on the printer is not finding the right driver. if you used asus's disk that should have found the mobo device, if it was unknown. how about your video card? sometimes there is an audio driver associated with the hdmi output that sometimes needs programming for.
is your raid intact, and the sata controller still in raid mode?
this page may help give a clue, need some of the info if you hit properties on the device in device manager and find the right string.
have you done a windows update lately? did it try to update any of the hardware?
my main rig...
asrock 970 extreme3
AMD athlonII X3 440
zalman cpns5x performa hs/fan
crucial ballistix 2x4gb sport ddr3-1333
powercolor ax7750 1GBK3-H vga
antec neo he 650r
Samsung 840 EVo SSD 120 GB
toshiba 2TB HDD 64M cache sata3
seagate 1TB HDD 64M cache sata3
hitachi 2TB HDD 64M cache sata3
lg wh14ns40 bd burner
optiarc ad-7240s sata dvdrw (nec chipset)