Booting Win XP cd from DVD drive

I told the chap in the shop about all this, but he says that I will HAVE to boot from the Win XP cd!

I have changed the DVD to a cd drive, I have formatted the hard disk, I have tried so many times to get this installed, but when I run the setup (winnt) file it copies all the files OK (apparently), it takes ages to do this, but then fails on the install, saying it cannot read various files.

Today I got another CD which should be bootable, it is a Ghost setup disk that used to put a whole Windows 98 and applications on PC that I had to load at work years ago. This will not boot either, although I am sure it did previously as I once loaded by mistake when I switched on with this cd in the drive.

The PC boots OK from floppy and HD but on both the cd drives I have tried, it looks at the cd as soon as I switch on, but will not boot, if there is no other boot device it reports no system disk present. As soon as I load a 98 boot floppy with CD support I can see and use the cd drive. So why does it not boot? I felt sure I had a win XP cd problem, but now I find it will not boot from this Ghost cd either, I don't know what it can be. The setting of the boot devices seems very simple and straighforward, I am sure I am not making any mistakes. The Shop says it is the only way and is too busy to help further. I reset the bios to the default values, in case there was a problem there somewhere.

I really need to get this working on XP as Win 98 is very unstable and I despair of ever getting it running like my Laptop.

Any more ideas? Please.