If you have reasons that cannot repair windows and cannot format your windows including windows server, You can follow up as belows.
1) copy NTDETECT.COM and NTLDR from I386 to C:\ ( should be primary root partition )
2) sometimes it will ask you again HAL.DLL file after copied NTLDR though
3) need to repair and replace boot.ini file
Enter Windows/Windows Server Recovery Console. The Recovery Console is an advanced diagnostic mode of Windows with special tools that will allow you to restore the boot.ini file.
When you reach the command line (detailed in Step 6 in the link above), type the following command and then press Enter.
bootcfg /rebuild
The bootcfg utility will scan your hard drives for any Windows XP installations and then display the results. Follow the remaining steps to add your Windows XP installation to the boot.ini file.
The first prompt asks Add installation to boot list? (Yes/No/All).
Type Y in response to this question and press Enter.
The next prompt asks you to Enter Load Identifier:.
This is the name of the operating system. For example, type Windows XP Professional or Windows XP Home Edition and press Enter.
The final prompt asks you to Enter OS Load options:.
Type /Fastdetect here and press Enter.
Take out the Windows/Windows Server CD, type exit and then press Enter to restart your PC.
Assuming that a missing or corrupt boot.ini file was your only issue, Windows should now start normally.
http://support.microsoft.com/kb/816793
I've Got successfully fixed in this way.
