If the manufacturer of the card provides Windows software to "migrate" from non raid to Raid 1, then yes, some Intel raid controllers and software allow this, not sure about Promise, I suggest you contact Promise support for a definite answer on this.
Promise does suppy "WebPam" software for Windows, maybe it allows for migration.
Select your Product then your Model, you will find the Software and other material for your product.
User Guide for the TX2300
After looking through the guide, It appears there is no "migrate" function, it only allows you to set up a new raid volume using "free" logical drives,