Transferring files from my old Dell to my Macbook?

I have been using my WD Passport  as my Time Machine on my Macbook since I got it a few weeks ago. But I recently realized I needed to get a lot of files from my old Dell. So I was planning on unformatting my Passport from the Time Machine so it’s just a giant USB device that I can drag and drop items to.

Here’s the problem:

I can’t access the hard drive on my Dell anymore. It still shows up as a “device,” but I can’t drag items into it. On my Mac, I can drag whatever I want onto the drive, but I can’t access it on my Dell.

Any help? Thank you.

It’s because it is formatted for Mac. This might help HFSExplore I think it’s the only free utility like this. For a pay one there is MacDrive. Can you network the 2 machines and transfer things that way?