Hi Simon,
There are several ways to do this:
1. Depending on your BIOS, you may be able to boot to the cd-rom which should allow you to start the install process and create the NT boot Disks.
2. You will need to use a floppy boot disk thathas the cd-rom divers on it. Once you can access the cd-rom you should be able to install.
3. You can create the NT boot floppies on another computer and boot to them which should install cd-rom support during the setup process.
4. You can do a remote install using another computer. The two computers need to be on the same network and and you will need a Network Installation Disk.
5. You can install Win98 on the same machine and then install NT from within win98.
Hope this helps.