I have a question in regards to the server that we currently purchased. It currently has (1) 1TB HDD installed and I want to look to improve data redundancy by implementing RAID 1. My question is if I install an identical 2nd 1TB HDD and setup for RAID 1, will it wipe the first disk and start fresh or will it begin to copy everything to the new 2nd HDD?
Assuming that it is not already configured to use RAID 1 with only 1 drive (highly doubtful), you will almost definitely be forced to wipe the first disk when you setup the RAID 1 array.
Since you are using good backup techniques (right? You are, aren't you? ;) ), it should just be a matter of making an image of the current drive setup before you setup the RAID 1 array and then restore from that image after the array is setup. You might then need to install some RAID drivers/software in Windows.