This dongle works great! My 200 gb IDE WD HD shows perfectly on my DELL E521 in addition to the SATA drive it came with.
You'll need 3 things besides this dongle - extra floppy power connector for the dongle, standard molex power cable for the HDD, and a SATA cable to connect the HD to the motherboard. Glad I ordered an 18 SATA cable - anything less would be too short to reach on my mobo. BTW, these guys have GREAT customer service!