Hi all, Could someone explain me the difference in methods of booting Windows XP from external USB drive? As far as I learn from websearch there are two methods: 1) building bootable USB drive with help of BartPE 2) building bootable USB drive by replacing certain files in the XP_CD_image. I've chosen the second method to build my USB_install_XP_disk and unfortunately shortly after beginning the installation on USB drive the message "Put a disk marked XP ServicePack 1 into drive a: and press any key to continue" appears on the screen. I tried to mount the CD with Service_Pack1 but without no avail. This was when I was installing from the modified image of version containing the Service Pack 2. When I tried to rework an older XP version from year 2002, not having any Service Packs included, it was a bit better but then the installation stopped and a message "In the file *.sif used by the installer the following information is missing or incorrect: value 1 in the section [InputDeviceSupport] with the key "usbstor". You cannot continue the installation. press F3 to quit the installation" I checked the replacement files carefully for any errors but evrything's according to the instruction. What's the matter with this method? What is the advantage/difference between those tho methods? Can you help me? Thanks in advance! Zennon

I'm not aware of any way you can do this via software by pointing to a drive letter, as the drive may not be the same on every machine. Why not just set Removable Devices as first boot option in the BIOS? Life's more painless for the brainless.

As Jenn said, going into your BIOS and setting Removable Devices as the first boot option is the way to go. A buddy I work with has Windows XP as well as Ubuntu Linux on two seperate USB drives and can boot right off of them without a problem.

Years ago I tried to accomplish what you are now trying to do. It won't work because Windows XP itself will not boot on anything other than internal HD. i_XpUser

I've a working xp on usb external hdd. It works on that computer only. Xp BartPe is a better choise & works on almost any pc.