I think your first port of call may be your motherboard manual. If it supports RAID 1 then that saves a few pennies which would otherwise have to be spent on a controller card.
More knowledgeable members may have a workaround but I think you'll find that adding a second hard drive (same size and similar performance) and configuring the two as RAID from the BIOS means wiping the first disk. If you can't effectively back it up then that means getting two new disks for your array and using the current disk as a, possibly temporary, D: drive so you can copy your data across to the new array after you've installed an OS. At least one of the drivers will be different on the OS because of the RAID so I'm not sure that using Norton Ghost is going to work as far as restoring a disk image is concerned.
This may all be sounding rather negative and I'll make it worse by observing that using a second drive inside your computer to guard against failure won't help you in the event of either a power spike or theft. My own preference would be to first spend my pennies on more removable storage and only after that spend money inside the computer. But that's me and others may have equally valid (or better) strategies.