Use a 1 TB HDD in MSI KT6 motherboards

Have you tried visiting MSI's website? They most likely have the information on your motherboard's description page.

That is an old board for sure, but it does support SATA 1.
You will have to set the jumper (which is jumper number 5&6 on Western Digital drives) on the drive to make it compatabile with your SATA 1 interface, but it should work.