External Passport was for Windows, now using on MacBook

It sounds like you’re trying to use a Western Digital (WD) My Passport external hard drive that was previously used on a Windows PC, and now you're trying to use it on a MacBook. You mentioned "500 work", which may be a typo—if you meant “500GB not working,” or something else, feel free to clarify.

Here's how to troubleshoot and get it working on your Mac:

Step 1: Check if Mac Detects the Drive

Plug in the drive.

Open Disk Utility (Search with Spotlight: Cmd + Space → type "Disk Utility").

Look under External on the left pane.

If it's showing up but grayed out: click and choose Mount.

If it's not showing up at all: Try another USB port or cable.

Step 2: Understand the File System

External drives formatted on Windows are usually in:

NTFS (Windows format – Mac can read but not write)

exFAT (Both Windows and Mac compatible)

FAT32 (Older format, limited to 4GB files)

If it's NTFS, your Mac can read but not write without additional software.

Step 3: Fix or Reformat (if needed)

If you just need to read files, NTFS is fine.

If you want to write files, either:

Use NTFS write software for Mac (like Paragon NTFS for Mac or Tuxera NTFS).

Or reformat the drive to exFAT (WARNING: This will erase all data).

To Reformat:

Back up the drive’s data on your Windows PC first.

On Mac: Open Disk Utility → Select the drive → Click Erase.

Choose Format: exFAT

Scheme: GUID Partition Map

Click Erase.

Final Check

Once reformatted or with NTFS software installed, try dragging files to/from the drive.