external with system wont mount


Thinking I could shortcut an upgrade I dragged an entire hardrive with OS 10.2 and 9.2.2 onto an an external 80gig LAcie FW thinking I could just drag what I wanted back after upgrade of system(like email). Now emac will only format it but not mount it. I can see the drive with Dataviz on a pc. Re naming the sytem folders didn't allow mount on the mac. Are there files I can delete or remove that will let this drive mount so I can drag stuff back. I can see the files through the network on the mac but dragging them over doesn't work.