I just bought a brand new PC, the only old thing was my harddisk which i put in. When i started it up, it brought up the error message
"K8 NPT Data Change....Update New Data to DMI!"
It did this every time

Just to check, i put in the new harddisk that came with it, and had the windows xp pro startup disk in the drive. I booted from the cd, and it formatted the new harddisk, did a pre-install and then re-started the pc. When it restarted, it got to the same error message before going to the windows install.

I can't get past this point, can anyone help?

If it helps, the harddisk is a GeForce 6100SM-M, with an AMD2 Athlon 5200 (dual core) CPU

Oh, if i put my old harddisk back in my old pc, it still works fine.

thanks for any help!

Welcome to PCHF.

First, you can not just install an old C: hard drive from another PC into your new PC. The computer won't work that way. In order to do so, you need to reinstall Windows onto the old hard drive while it is in the new PC. But then you can not return the old C: drive to the old PC.

Decide which hard drive you want to use as the C: drive in the new PC.
Install that hard drive into the new PC.
Place the XP Pro Windows Installation CD into the CD drive.
Boot up into the BIOS and exit by saving the default setting (configuration).
Reboot via the CD. When asked, reformat the C: drive to insure a clean hard drive.
Now you should be able to install the XP Pro into your new PC.

thanks for the advice - but i had tried it already

when i boot up from the windows cd with a brand-new harddisk in, the windows setup formats the drive and restarts to install, but when it restarts i get that error message and it doesn't go anywhere

i've tried everything i can think of and cn't get past that error message

Forget about that old hard drive for one moment Craig ok, what happens when you boot this brand new pc up normally?
Simply just turning on the new pc.
I hope to god you haven't formatted XP off the drive that came with it.

this is with the new pc and the new hard drive - it came with no OS installed

Suggest you take the PC back to the store and tell them the PC is broke.
Do NOT tell tell them you removed the hard drive.
Just tell them that the computer will not install Windows.