|Bios seeing it is a start. Shows that the memory chip on the drive is still OK and a few of the data lines are intact. We used to hide info in the memory region of the hard drive for testing.|
All that doesn't prove that the platten can deliver any data to the OS.
The simple answer is if you can't mount it you can't easily get data off. You could mount it raw and use it that way but it gets complex.
Might look at barts/ubcd4win and unstoppable copier or some of the diag tools offered at runtime.org and others.
"Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, are in my top 10