It's a long story, and I have to admit right up front I think I did some pretty dumb mistakes during the process.

Ok, a G5 at work is dead (likely to be a logic board issue). I need to boot from the system (running in Leopard) in order to retrieve some custom settings in the program Matlab and the genuine software environment is needed. But as all the rest of the Macs we have are Intel based, I need to reformat the drive with GUID partition table (from what I read so far) in order to boot form that drive.

So I went ahead to try creating a disk image of the G5 drive (130GB of data). Either Disk Utilities or Carbon Copy Cloner were not able to do that. Disk Utilities said it is too large. CCC just said it could not complete the process. So after some discussion with coworkers, I backed up the drive, but instead of creating a disk image, I simply "select all" and dragged all the files onto an external drive (now I think I might have screwed it up by doing so.... )

Then I reformatted the drive with GUID partition table, and copied all the files back to the newly formatted drive (Yes, this is a stupid idea, I destroyed the original disk...)

Was going to boot from the newly formatted drive with original data from my MacBookPro (running in Leopard) using firewire 800. The drive showed up as a bootable drive but after a second it showed an error stop sign and went back to boot from my internal drive.

So my questions is, is this drive still recoverable so that I can boot from it? Or I screwed it up completely already?