Right PROBLEM SOLVED.
For anyone in the future this is what i had to do.....
Physically change the jumpers on the motherboard to enable the SATA / RAID controllers. Details found on the motherboard manual available at the ASUS website
Update the BIOS to v1008
In BIOS....enable SATA/SCSI (now available scinve BIOS version 1008)
and set 2nd boot device (behind floppy) to HDD-1. (in advanced menu)
- (my old HDD was set as HDD-0) - though i never ran both at the same time.
- I worked this out by chance..after enableing the RAID controllers i got another screen when booting up showing all SATA devices. i noticed that it said 1 - WD******** so as a last ditch attempt i went back to BIOS and changes the 2nd boot device to HDD-1 and hey presto it worked.
Next I had to install the SATA drivers using the F6 function before Windows installs. Restarted and it all works fine now.
Thanks all.
Hope this saves someone a headache or 2. I never phoned for any technical help as I decided I wouldnt be able to explain what I had done..lol