NTLDR problem on new XP install

I am trying to replace the HDD in a Sony Vaio VGN S1-XP but the CD drive does not work (appears to be a known problem with the Matsushita drives in this model).

So, I have been following William Wilson's tutorial - Install Windows XP without floppy or cd drives.

All went well until I refitted the new drive back into the laptop. I ran the WINNT.exe which copied all the files from the CD (or in my case, the newly created I386 folder on the HDD). It then got to the stage of the first reboot and I got the dreaded 'NTLDR is missing, press any key to restart'.

I have looked around at various causes but can't find any real clues. As it is so early in the process, I can't access the command prompt to look around, I can't boot in Safe Mode (F8 seems to be ignored) and can't access the rescue console.

I have tried it about 3 times, double checking each step with no luck.

Any ideas anyone?

Thanks