Hi,
On a not well known 5year old SATA "Excel Store" HD with XP, suddenly IE would start to freeze the PC. Sometimes waiting a few mnts would unfreeze & gradually the PC was alsmost unusable.
I thought perhaps a virus affected IE & decided to install Ubuntu 8.10 but since the PC would not boot & giving "NTLRD missing".
1) Put your XP cd into the system
2)Boot the CD
3)Log into repair console
4) change directory to cd/dvd drive and go into the i386 folder
5) type 'expand -r HAL.DL_ C:\WINDOWS\system32'
Change "recovery" to "repair"
If this could not help you out then you need to format the system. Before format take the backup otherwise you can recover lost data from third party tool like Recuva, Stellar windows data recovery software and many more.
If u want to take backup of your data then use mini xp which boots from cd & give you access to all your HDD. so u can easily move data. In Hiren's Boot CD Mini XP is included.