You experience this symptom if the following conditions are true:
1. In the BIOS, a universal serial bus (USB) removable device is set as the start device, or the USB removable device is set to a higher priority than the first hard disk drive in the start order.
2. You attach a non-bootable USB device to a USB port before you start the computer.
3. You try to install Windows Vista from DVD installation media.
CAUSE
This issue occurs because the Windows Vista installation must be able to write to the boot volume of the computer, and the boot volume must be non-removable to prevent later removal of the boot device. If the boot device were removed, this would make it impossible for Windows Vista to start. A computer is restarted several times during installation. Because the BIOS reports the USB device as the boot device, and the USB device is removable, Windows Vista Installation cannot continue. This is by design.
RESOLUTION
To work around this issue, use one of the following methods.
Method 1
Remove the USB removable device before you turn on the system. You may insert the device after Windows Vista installation starts.
Method 2
Change the BIOS settings so that the USB removable device has a lower priority than the internal hard disk drive and the DVD drive.