Mac to Pc back to Mac not recognizing... please help

Hello- I have a my passport ultra that was on my mac, but a friend put in their PC. I put it back in my mac and it worked, then all of a sudden today it stopped recognizing it. They told me of this and I can see everything on the PC- is there a way to reformat it back to my mac? Please help. Thank you in advance.

If you reformat you will erase all data. Maybe your friend already reformatted it for Windows so he could use the drive!

He didn’t though- he just put it into the computer… I can see it all there. I am thinking if I put all the info on Dropbox and then learn to reformat I may then be able to get it back to MAC and then put back on my drive?

Not a good idea. If you can see the data but just not able to access it, I suggest you reboot your computer and either have the drive attached or put it on after reboot; whichever you normally would do.

Here’s a tip: Never let some one with a non-apple computer attach your drive to theirs. If a mac-formatted drive is attached to a Windows computer (or vice versa) the computer cannot read the drive, and the computer, not being able to read the drive asks if you want to format it, and if one answers Yes, the drive gets formatted and it is toasted because all data got removed! It seems your friend answered No since it appears your data is still there.

You also might want to ask your question at the Apple forum, since this appears to be a computer issue and not a drive issue.