Raid card installation without re installing Windows

My problem is as follows…

I have a Dell Poweredge SC440 server.

It is equipped with two disks. One is formatted into two partitions “C” and “D”

The other is unformatted but otherwise is identical to the first. It is recognised in “Computer Management – Disk Management”

The formatted disk is running Windows Small Business Server – all is working fine.

I have a Promise Fast Trak TX2200, TX2300 raid card that I want to install as a raid 1 mirrored installation.

According to the Fast Trak documentation it is possible to install the card without having to re install windows.

But the instructions are not that clear (of I’m a bit thick! – which is the most likely)

Has any one had experience of doing this?

Does the unformatted disk need to be formatted or will the raid system mirror the formatted disk when installed?

Any help or advice would be gratefully received.