How to store all stored data in my Elements HD before I reformat?

I bought a new Mac in August. Just assumed my external HD was saving everything. Shouldn’t have assumed. Does my HD need to be reformatted for my newer OS? Could that be problem?
Apparent;y if I do so , all of my data will go by-by. So…what happens to all the years of data that is on it currently.


It depends on what OS you were using before. If you had another Mac, you might not need to reformat the drive. Now, if you were using the unit on a Windows computer, the drive might need to be reformatted in order to use it on the new OS.

If it was a Windows Pc, I’ll recommend you to save your files first on another Windows and then reformat the drive for both systems windows and Mac so you can transfer the files manually, copy and paste.

If it was another Mac that you were using before, you don’t need to reformat the unit, just plug it in to the new system and transfer the files to it.

Thanks for the quick response.
I have always had Macs. Transitions have always been fairly smooth except
for this one.
I could be missing something though. I admit I’m not perfectly savvy about
I went onto my HD and searched for fairly new data, but couldn’t find some
of it.
Know my HD is supposed to only save ‘new’ stuff as it already has the old
stuff stored.
I’ll attempt to search for some new stuff and see if I was just overlooking
it somehow.