When booting I can't have my external USB 2.0 hard drive turned on or else I get the message "Invalid system disk, please replace"

Problem

When booting my one of my PCs that runs Windows XP and has an MSI motherboard, I can't have my external USB 2.0 hard drive turned on or the error message "Invalid system disk, please replace" comes up. The PC boots fine if I leave the drive switched off and then turn it on after Windows has loaded. After the Windows XP logo appears I can turn the drive on. On my other computer that has an Asus motherboard, there is no problem starting up when the external hard drive is switched on.



Answer

Check that you have set the boot order of devices in the BIOS to the order that you want them to boot. In a Phoenix Award BIOS, there should be a setting called First/Second/Third/Fourth Boot Device on the Advanced BIOS Features page of the BIOS. The wording for both of those categories will be similar in another make of BIOS. This setting allows you to set the sequence of boot devices from which the BIOS attempts to load the operating system (Windows, Linux, etc.)

On the same page in the BIOS, there should be other settings called Hard Disk Boot Priority and CD-ROM Boot Priority. Those settings allow you to set the boot priority of the hard drives and CD/DVD drives installed in the system.

If the problem isn't fixed by correcting those BIOS settings, try downloading and installing the latest drivers for the motherboard from the MSI site, and, if you still have the problem, try updating the BIOS itself, which may have a bug that is rectified by the update. The motherboard manufacturer's site provides BIOS updates and information on the ways in which they can be installed.