Ten months later, we've got around to buying a new hard disk. It installed fine, and the BIOS says that there's an IDE connected but the laptop has no floppy or (internal) CD-ROM drive so I have not a clue as to how to reinstall Windows. I just figured that I could hook up the external CD-ROM drive (which came with the laptop) and use that to re-install. I found someone with exactly the same problem and the same laptop on Google here if you'd like to know more.
The only way I can see to move forward is to try booting via PXE, but I've no real idea how to do this. I've heard that you can install a PXE server in Windows, or you can use Windows Server's "Remote Installation Services", or there are Linux versions. I could do with somebody giving me a push in the right direction. I can get copies of Windows Server 2003 and 2008 for free through college, so price isn't a factor... I'd just rather whatever's easiest really.
Any help would be much appreciated, since we've got a perfectly good laptop going to waste at the moment.
P.S. Some things I found on Google that might be helpful?