Hope someone can authoratively answer this. I have 3 files on a USB pen namely NTLDR, NTDETECT.COM, Boot.ini I believe my ( XP HE ) system only requires these to boot ( I Could be wrong ). I have Boot order set as USB ==> CD ==> ==> HDD I have tried booting with USB pen connected and I boot-up OK but ..... ... how do I know I have booted up off the USB device ? I ask this because it would be nice to know that precautions taken are indeed effective precautions. Ta for any responses.