New macbook user since Christmas and not a technical person--struggling through alot of data transfer since new year. Mostly successful until today. Yesterday, transferred iTunes folder from PC to External Seagate Hard Drive, plugged harddrive into my Macbook Pro, transferred successfully and now NO data on the Seagate. Cannot read the Seagate from the Mac (although I could when I transferred the iTunes folder yesterday); CAN read the Seagate from the PC, however, no files are there. We had tons of photos, videos, personal data on the hard drive. I'm in the doghouse right now, so please let me know if there's anyway I can recover or if I just learned a easy lesson the hard way. Thank you for reading this and if you can help! Success! Recovered Files/Learned A Lot I recovered the data with File Scavenger (Windows //www.quetek.com/prod02.htm) . Because the PC could still read the external drive, I was able to purchase and use a program called File Scavenger to recover 360+GB data. Although some of the lost data had been copied, much had been moved from old machines, so there were no other copies--luckily this recovery worked. Thank you to those who reached out to help and I hope this might help others.