-You try use HDD Regerator in Hiren's Boot disk ,test HDD (bad sector) ?
-You Sure Active HDD and -> BIOS ->first boot (HDD)
IF the problem not fix,you try step by step:
1.Insert the Windows XP bootable CD into the computer.
2.When prompted to press any key to boot from the CD, press any key.
3.Once in the Windows XP setup menu press the "R" key to repair Windows.
4.Log into your Windows installation by pressing the "1" key and pressing enter.
5.You will then be prompted for your administrator password, enter that password.
6.Command Promp ,You write -> chkdsk /p (test HDD and backup folder boot)