I doubt it is a boot.ini issue, this file (if it even exists) is created during the installation, and it sounds like you are still not even getting through the entire installation.
*Assuming you are still using my tutorial as a guide to install XP*
This may be an odd thing to try, but MS has known issues with the NT filesystem and large files on the root drive, they are documented in many places, including:
Windows may not start and you may receive an "NTLDR is missing" error message if Windows is not up-to-date and there are too many files in the root folder
and the .cab files which are compressed collections of the Windows OS are fairly large, especially for the FAT32 filesystem which this process requires.
Format the drive as usual, create 2 active partitions, 1 for DOS small and on the front of the drive, a 2nd larger after DOS (DOS must be first it may not boot elsewhere on the drive) for XP.
Then add an extended partition on the end, doens't need to be huge, but large enough to hold the i386 folder. Separating the install folder and installation partition may help. Especially if the i386 partition is on a non active partition.
I recently ran this process on my laptop again, and found that it is much more consistent with these settings. Separating the OS is useful should you ever need to reformat and install, as you will not need to remove the hard drive, all the files and DOS will already be on the drive
Forgive me if i missed it in all the previous posts, but have you tried starting the installation from another computer?
Use the desktop to start XP installing, when it attempts to reboot for the first time, hold you power button so that it will not restart, and place the drive back in the other computer, when it starts it should continue the installation process, thus setting up your proper hardware devices.
**The NTLDR missing is a common error, and rarely does it have to do with a missing file, unfortunately this is one of MS blanket errors that appears for one of a many possible reasons...