How to resolve HAL.dll, NTLDR, and many boot failure errors in Windows XP and Windows 2000

1. First reboot your PC and when the Windows progress bar appears press the F8 key.
2. Once you press F8 the choices presented may include Recovery Console
(Recovery Console is an optional feature that is sometimes included in
startup so hopefully the manufacturer of your PC included it in your F8
options). If Recovery Console is not an F8 menu option then proceed to the next step. Skip to step 8 if the Recovery Console option is available.
3. Obtain a Windows XP or Windows 2000 installation CD/DVD, place the CD/DVD into the CD/DVD drive of your PC and then reboot the computer.
4. If the computer fails to boot from the CD/DVD disk then you will need to change the boot order of the PC so that the PC is configured to boot from the CD/DVD drive first. To change the boot order, reboot the PC and then look on the computer display for a message that instructs you to press a specific key to enter "Setup" (the key is usually F2, F12 or Del). Press the key QUICKLY and the display will then redirect to the Bios configuration pages for the PC motherboard. Navigate through the pages (usually using the up and down arrow keys, tab, and the page up and page down keys) until you find the "Boot Order" menu.
5. Next, move the CD/DVD drive to the top of the list.
6. Save the motherboard Bios boot order configuration by either navigating to the "Save and Exit" menu item or by pressing F10 (most motherboards support the F10 save configuration option).
7. Now reboot the computer with the Windows installation CD/DVD and let it run through the system check process. When the menu option to press R to enter the Recovery Console appear, press R (and in Windows 2000 press C to start the Recovery Console), and then select the Windows installation that you need to repair.
8. Once you have selected the Recovery Console your PC will display a command prompt and ask for your administrator password - enter the password and you will be logged into the Recovery Console.
9. The two options that you need to use to resolve the boot issue are Fixmbr and Fixboot. Fixmbr is a tool designed to repair a corrupt Master Boot Record on your hard drive. Fixboot is a tool designed to edit boot files such that they point to the correct location of the Windows system files. Type Fixboot and then press the Enter key and then reboot. If the issue is not resolved then go back into the Recovery Console and type Fixmbr, press the Enter key, and then reboot.