dont use cgminer. it requires special winusb drivers and some sort of proprietary communication method.
BFGMiner uses the official Silicon Labs CP210x USB to UART Bridge VCP Driver, which is install once, and done. BFGMiner will detect all USB miners without a problem, and even supports hot plugging.
My CGMiner uses CP2102 USB to UART Bridge Controller and supports hot swapping of Block Erupters.
yeah i agree i use the same setup with cgminer and it works perfect , download the siliconlab drivers and you will be fine, have you setup your batch file right?