Failure to install Ubuntu 8.10

Hi

I have had repeated windows problems so though would switch to Linux. Have removed my old master hard drive (as an emergency backup) and have a 32Gb hard drive which I have made my master which has nothing on so perfect to install Ubuntu.

I am running: AMD Athalon XP 1600
512Mb of Ram
DFI Lanpart NF II Motherboard
GE Force FX 5600 Graphics card

I have downloaded the software from a mirror, checked the MD5 Sum, checked disk for errors from first Ubuntu menu and also checked my memory from the same place.

Everytime I try and install I get the Ubuntu logo on screen with the activity bar moving underneath and after a minute or two get a screen with the following information on:
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Loading please wait…

Busybox v1.10.2 (Ubuntu 1:1.10.2-1ubuntu6) built-in shell (ash)
Enter ‘help’ for a list of built-in commands.

(initramfs) [ 76.352067] ata 2.01: revalidation failed (errno=-5)
[ 76.352148] ata2.00: revalidation failed (errno=-5)
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The machine then hangs here before eventually rebooting itself.

I have no idea what to do next and am not a very technical person so any help available would be greatly appreciated.

TIA
Rob