Don't ever use any "special" editions of Windows. Nine times out of ten, they're infested with keyloggers and other AIDS.
Alright, I had a Dell Latitude L400 before. It's dead now because of zipper failure. The system fell right out of the bag and POW, right in the kisser. Goddamn Targus... but I digress! The way I installed XP on that POS is as follows:
The L400 requires EXPENSIVE cables and PROPRIETARY DRIVES to boot from CD or floppy. Screw off, Dell.
So what you can do is go on ebay, and order a 2.5" HDD to 3.5" adapter. It's just a little board with connectors on both ends of it. Shouldn't be more than a couple dollars, shipping included. Now comes the fun part. You download the disk images for DOS 7.10 from
http://ms-dos7.hit.bg/
Write them to CD or floppy, whatever, you'll need a desktop for this part. Connect your L400's HDD to the desktop, optionally, disconnect all other HDDs to prevent accidental catastrophic screwups. Boot the desktop to wherever you have DOS 7.10. Now you'll use DOS 7.10's setup to install DOS 7.10 onto the L400 HDD. Yes, this is dragging on, but blame Dell. Once you have DOS on the HDD, copy WinXP's installation disc onto the drive. Do this any way you like, USB, booting from your primary drive on the desktop and copying from there, whatever.
Once you have DOS 7.10 bootable on the drive, and XP's installation files copied onto it, shut down the desktop, remove the L400 drive, and put it back in the L400 caddy, then into the system. Now you boot the system. You'll start in DOS, naturally. From here, you jump to the directory of WinXP's installer. Say, c:\winxp\i386
Now run winnt.exe
This will start a DOS-compatible Windows XP installation. When XP is done installing, you can ditch DOS 7.10's directories and whatnot, you don't need them anymore. The reason you use DOS 7.10 is because it's FAT32 compatible. Makes it a LOT easier to install XP when you're not stuck with a 2GB primary partition. You can convert the drive to NTFS without formatting after XP is installed.
XP should have all of the L400's drivers in it from the get go, at least the network driver, so you can at least use the internet for the rest.
) on my Dell L400. It has no CD or floppy drive so I googled about and found at about putting on a usb stick, 3 hours later after the xp whole disk had been copied to my flash drive I find out that my laptop doesn't support usb boot 
.
