To install XP on any of these new(er) Laptops, or indeed any Desktop PC which uses S-ATA instead of the "normal" IDE A-ATA (which is basicly a dead horse), you'll need to have some S-ATA/RAID Drivers handy.
Now on a Destop w/a Floppy Drive this is not a gigantic problem as your still likely to have a Floppy Drive, or at least an older PC lyinground somewhere, where you can salvage One. Once you have it hooked up to the Computer in question you just start up the "Install Media" (e.g. XP), let the fist message about "ASR - press F2" fly by, and wait for the "Add SATA/RAID Drivers press F6" by pressing the F6 (Function 6 Key), you will of course need some Drivers on those Floppies. In the case of your Amilo Pa 2548: That would be the nVidia nForce MCP67MD
Once these Drivers have been installed you can continue on your way in a not so dissimilar way that you have always come to expect.
But alas we are talking about Laptops, and when was the last time you saw a Floppy Drive on a Laptop? It's probably been awhile hasn't it? So is there any other way to get these "Drivers" installed? Well you could use the above method w/an USB Floppy Drive, but how many People have a USB Floppy Drive? I sure do not, and I'm guessing that neither do you. (but, if I'm wrong.... Then you already have your answer!).
If I'm not however then there must be yet some ~other way~ surly, what about NAND Flash? (i.e. Memory Sticks, Pen Drives), well guess what?? XP does NOT support such Memory devices
So how do I get these Ficskin' Drivers to install then!?!?
The answer is to have the "Driver(s)" already installed to the Install Media to begin with, with the Drivers on the Install Media you won't ever need to worry about having to install the additional Drivers (e.g. Sound, Video, Ethernet & Chipset) again. SOUNDS GREAT! Now how??
Use nLite (http://www.nliteos.com/
), to build yourself a new XP Install Disc w/SP3, Hotfixes (Think Patch Tuesday Updates), Drivers (XP versions of the Drivers that you can find HERE: http://www.fujitsu-siemens.com/support/downloads.html
), and then with nLite burn your creation onto a CD/DVD and enjoy...
That's about the only only real option most people here have to get XP installed...