Help me!!!!!! Castle Link problem!

[BL_RV0]

Guys, I'm on my 2nd castle link now. I'm trying to connect me MM to the usb cable, and when I do it says there is no controller or an invalid controller connected. I returned and exchanged the first problematic one to my LHS and they said it had to have been faulty software. They exchanged it without any hassle. I followed closely Castle's tech support- no dice. I tried plugging it into all different usb ports on my computer, thinking one of them may be bad. I try to reinstall the driver as it says to do on castle's site, but it says cannot install hardware. I do have the CD in when I do that. When it is plugged in, there is a solid red and green light on the ESC. I switch it on and off, no change. It did the same thing with my sidewinder, which I bought new, so I know that's not the problem. Please help, this is the only thing standing between me and driving my hyper st! HELP!!!!!!