Have you read thread Paragon Alignment Tool (PAT) ?
Always clone or take a full backup of an HDD/SSD before running anything like PAT.
Since you mentioned XP, you also may be interested in thread Easy way to Enable AHCI on XP running in IDE mode . Note that first post is garbled so start reading at corrected second post.
Thanks for the response.
Seems I encountered PAT a couple of days too late.. :>)
I believe my rig is already running in AHCI mode... won't boot if other is selected.