Nano is not detected in windows 7, 64 bit

Greetings, I have been troubleshooting a very strange issue. I have some Nanos that I want to program but windows device manager does not even see that they are plugged in. I've tried multiple cables, multiple boards, and I have the FTDI drivers installed. But no matter what, when I plug it into the USB nothing happens. Not even a windows New Device prompt.

Is their something I am missing?

thanks, Justin

Are they real Arduino boards, or clones from Ebay ? Perhaps you can remove the device drivers, and check in the Device Manager if they are unknown or not detected at all. The first thing to do is to plug it in another computer, to see if they are at least detected.