did this happen right after U did the "USB drive" procedure? or you actually have the phone connected before but now it won't connect again?

If this happen right after you did the "USB driver" procedure, then it maybe the "cable connection" problem. If you actually had it worked before but now you cant connect, then ill say try to reflash the phone, there is problem some problem with the software in the phone.

Also, check your phone's battery. make sure its fully charged or at least have power to run some modification and so on...