I've gotten that blue screen with white lettering that says "If this has happened before..." several times, before.   Usually it does'nt casue a serious crash, but for the times it ahs, I've been able to contribute them to kernel errors in the file format of the disk.  In other words wither the  hard disk, or the formatt of the hard disk have gone.

Have you tried to insert the Windows Xp Setup disk and then boot the system?  If you get anything, you may be able to reinstall windows.

You could open the bay to the HDD, and check the connection.  You may try unplugging replugging it in. 

Otherwise I'd check with CompUSA, etc. and verifiy it's not just the HDD, becasue the cost of replacin the main board will be more than the laptop is worth...I had a friend lose a mainboard from her Compaq Laptop.  Hey wanted $500 to replace her mainboard.  Instead she gave me the $500, I bought a used, but identical, replacement for the computer that died and pocketed $100!  Then the day after she got the new laptop, the old one started working again!  Now if either goes, she'll have plenty of replacement parts!