New 2nd Hard Disk -visible in Disk Management - but NOT in Explorer/Computer

Hi

I installed a secondary HDD in my wife's Vista Premium PC. It 'installed"
and drivers installed and Vista "says" your new HDD is ready to use.

However, in Computer/Explorer there is NO 2nd HDD and I couldnt "use it"....

I took it down to local computer shop. They investigated and told me that
the motherboard would only recognise 2 IDE devices (the first HDD and the
DVD Burner). They suggested that they replace the DVD Burner with an ATAPI
device (?) which I did OK and that then the 2nd IDE HDD would be
operational.

Now I DID rush them, and I didnt actually see it working, but paying for it,
I left the shop and came home with the PC.

Of course, the 2nd HDD is STILL not visible/usable in any way.

When I right click on My Computer and go "Manage" and go thru to Disk
Management, the 2nd HDD IS VISIBLE. I thought I may have to Format it. BUT
clicking on this brings up an error message that Disk Management has failed
and to restart your computer. I do, no help......

....and EVERY tiem I DO restart the computer the SYSTEM has changed screen
comes up 2 times:

1st.time ....Found a new HDD (the original, first HDD) hit F1 to accept
changes
2nd time... Found new HDD (NEW 250GB one) and LiteOn DVD Burner hit F1 to
accept changes

then correctly thru to normal Vista boot/login...

This is EVERY TIME I start PC....

Any thoughts/advice would be greatly GREATLY welcomed.

Rgds
Rod
Perth