Windows-generated serial

A USB instance ID made up by Windows when the device reports no usable serial, recognisable by an & in second position, as in 7&1f2e3d4c&0.

USB devices are supposed to report a unique serial. Many cheap readers and some sticks don't, and Windows then builds an instance ID from the port and hub path: 7&1f2e3d4c&0. The second character is &.

Such an ID is unique only on that computer and changes with the port. It is not printed on the device and will not match on another machine. Identify the device by vendor, product, capacity, volume serial number and timing instead.