Your computer cannot boot from USB, your CD ROM does not work, your hard disk has no bootloader. I don't know what you mean by external DVD ROM. If it is USB based then it will not work. If its some variant of ATA then just connect it inside your computer.
Now, in my opinion you have these two options :
- Attach a working CD ROM or DVD ROM.
- Remove the hard disk from this computer and attach it to another computer with working DVD/CD ROM.
After you have working CD ROM, you need to repair XP install.
You say you have 2 hard disks and installed Windows XP on D: (second drive). So all you have to do is install XP bootloader on C:.
Both hard disks must be connected in the same primary, secondary order when you do this.
- Boot into recovery console using Windows XP CD.
- Type the following pressing Enter after each line :