atmega16u vs atmega8u2

Hi all. Please tell me with some info about whitch is the difference between atmega 16u and 8u2. I bought from ebay one clone with 16u micro but when i installed on my windows 7 operating sistem it installed like arduino uno.After this i reburn the bootloader but it recognize only like at90usb82. Please give me an answer. Many thanks for yours help.

If you mean the 16U2, then the only difference is the 16U2 has 16kBytes of program flash, while the 8U2 has only 8kBytes of program flash.

Older versions of AVRdude don't recognise ATmega8U2 or 16U2 chips, and the workaround is to tell the programmer they're AT90usb82 or AT90usb162.