When you say you installed the "chipset" drivers, did you install a driver intended for the actual C222 chipset, or did you install the driver from the Chipset section on the Drivers and Downloads page for the R220 at support.dell.com? Here is the driver for the USB 3.0 controller: [URL] 
I'm installing Windows 2008 R2 on a R220. I've installed the chipset and NIC drivers, but there's still a mysterious USB Controller Driver missing. Any thoughts on what I'm missing?
Dell R220 USB Controller Driver