O Visualizador de Eventos do Windows 7 não registra tempos de montagem USB. Em vez disso, você pode usar o freeware chamado USBDeview .
USBDeview is a small utility that lists all USB devices that currently connected to your computer, as well as all USB devices that you previously used. For each USB device, exteneded information is displayed: Device name/description, device type, serial number (for mass storage devices), the date/time that device was added, VendorID, ProductID, and more...
USBDeview also allows you to uninstall USB devices that you previously used, disconnect USB devices that are currently connected to your computer, as well as to disable and enable USB devices.
Por favor, tente nos informar se isso resolve o problema.