SUPERB! You know the machine and gave a perfect answer. We need more folks who are so helpful.
The answer to go into the bios on the 531 and change the Sata ports to 1 and 2 was exactly the right answer. Worked like a charm. This is something I never would have found anywhere else and didn't seem to be in the owners manual. I am currently involved in a "project" to upgrade a 531 as much as possible with a new larger HDD and DVD writer and installing the max memory to 4gb along with a upgraded Athlon 64 x2 5600 at 65w. Hopefully this won't mean I need a bigger power supply too. If I have a problem, I will look to this community for solutions.
Glad this old thread was helpful. The upgrades you are planning should not require a bigger power supply.
Good luck with your project!
I'm reading that 2TB should not be a problem... I did found another thread that referred to the following link about updating the NVIDIA driver.:
I'm not sure what model of NVIDIA I have in my DELL so I can update the driver...
Here I am reading this in February 2018, because I have had the same problem when trying to install a 2nd HD in my Dell 531. Kudos for the solution that was given by dhwcaw Copper.
My headache is GONE!