Have a data drive which recently became unavailable and prevents Windows from booting up. The BIOS can see it. I've slaved it to another system, and after logging in, Windows runs the Initialize and Convert Disk Wizard as it recognizes it. In Computer Management, it appears as an Unknown, Not Initialized Disk with it's partition data Unallocated. I ran R-Undelete and it can't read this disk because it doens't appear as a valid drive.
What options, if any do I have before sending this drive to a data recovery service?