HAL.DLL is Missing
a) Insert the CD of windows xp and restart the computer. If prompted, select any options required to boot from the CD.
b) When the text-based part of Setup begins, follow the prompts and choose the repair or recover option by pressing R.
If you have a dual-boot or multiple systems, choose the installation that you need to access from the Recovery Console.
When prompted, type the Administrator password. (if you didn't create one try pressing enter).
c) At the system prompt, type: help (for a list of commands) or help commandname for help on a specific command.
You will need to expand the file from the CD:

The command would be expand d:\i386\hal.dl_ c:\windows\system32\hal.dll.

Substitute d: for the drive letter of your CD. Once you have expanded the file type "exit" to exit the Recovery Console and restart the computer.

Option  2:

Boot from your CD and follow the directions to start Recovery Console. Then:
Attrib -H -R -S C:\Boot.ini
DEL C:\Boot.ini
BootCfg /Rebuild
Fixboot

TIP:  Recovering Windows XP using the Recovery Console