into Google and got a similar story to yours, an Aliewnware 51 with an 80 Gb Hitachi mobile hard drive SATA ,
You'll find it here ( remember to hit translate this page in Google unless your German is better than mine ) : http://www.pcgames.de/?menu=0901&s=t...d=4380240&x=16
Either the hard drive is dieing or something bit your XP install ( It could be the motherboard connector but that's a long shot. ).
For the latter the Alienware manual will tell you how to reinstall the OS and all necessary drivers and programs ( You should have them on the CDs. ).
But you have to find out how to test the hard drive for bad sectors and if it should have them and have to be replaced you will need tech support.
I"m sorry you had a bad time with them the last go round but you have to talk to them now.
So email them with the error message.