I have an externally powered USB hub with a Flash Drive semi-permanently plugged into it. In constrast to an un-powered USB hub, it's my understanding that devices plugged into an externally powered USB hub are initialized, and will be recognized by the Windows operating system at start-up. This seems to be a truth that I have come to expect and rely on. Occasionally however, the flash drive fails to show or respond properly and it becomes flagged as a bootable drive in the BIOS. Does anyone know why the USB drive would show in Windows as expected one day but not the next, and so on? Would setting a password to access the BIOS prevent changes to drive status and would that prevent malware from accessing the BIOS? What are recommended Access Control List and Security settings for secondary or backup drives on which Standard Users need to store and change files? If someone has experienced and solved any such problems, I'd be grateful if they'd share the solution.

Hi, Please be noted that an external device need power to work. As a USB flash device, it commonly obtain power from the USB port on motherboard when you plugged it into your machine. Only if the device obtain enough power it will be recognize by BIOS. All these above are before the start of the OS. You said “an un-powered USB hub”, the correct name of it is bus-powered hub. A bus-powered hub is a hub that draws all its power from the host computer's USB interface. It does not need a separate power connection. However, many devices require more power than this method can provide, and will not work in this type of hub. In contrast a self-powered hub is one that takes its power from an external power supply unit. Also many hubs can operate as either bus powered or self-powered hubs. Please refer: http://en.wikipedia.org/wiki/USB_hub Notice: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this. If you want to troubleshoot a USB related problem. You may refer the following article: http://windows.microsoft.com/en-US/windows-vista/Tips-for-solving-problems-with-USB-devices The BIOS password mainly prevent access to BIOS, it will not influence drive status and cannot prevent any BIOS virus. Best Regards,Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Thank you zhen tan for the informative response.