Find a List of USB Devices Connected to Your PC
In the Registry Editor in Windows 7, you can find detailed information on devices connected to the USB ports of a PC under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\USBSTOR\
Subfolders will use the serial numbers of the USB devices, and the 'FriendlyName' field will show the brand name of the devices connected to the PC.