Serial numbers from flash drives can be two. First serial number is the alphanumeric code that the manufacturer indicates on the body of the flash drive. To learn it, take the flash drive and thoroughly inspect it. The serial number is usually placed at the back of the case, although sometimes it may be listed on one of the internal elements of the flash drive. In this case, in order to obtain your serial number, you will have to disassemble the drive. This serial number is not unique: the manufacturer marks this code all flash cards are the same model. So if each flash drive you need to assign a unique identification code, you should use the second serial number.
A second code, which can also be considered a serial number is written in software flash, if that had been manufactured to specification (as are the majority of modern flash drives). This room is called InstanceId and is unique for each flash (if the flash drive was not manufactured according to specification, the InstanceId is generated by the operating system).
To learn InstanceId, go to the registry editor (open the start menu - Accessories - Command prompt, at the prompt, enter the command "regedit" and hit "enter").In the registry editor, on the left is the folder Explorer. Using it, open the folders in this order: HKEY_LOCAL_MACHINESYSTEMCurrentControlsetenumusb. In the last folder "USB" will be a folder containing information on your flash drive. Opening it, you will see an alphanumeric, which is the required serial number.