Solved HFS+ from Mac to Windows - Formatted?

I was using an HFS+ 3TB Buffalo hard drive on my iMac and plugged it into my laptop. It didn't show up in Explorer but I think I may have formatted it in Disk Utility. Somewhere along the way, a dialog popped up that mentioned a choice between GUID and something else and I clicked GUID, and now it won't work on the Mac or the PC. Did I format it? It must have worked INCREDIBLY quickly to format 3TB in about 3 seconds....

Also, the partition that used to be there before doesn't show up in anything.

Here's some pointers that may hold a solution:
https://www.google.com/search?site=...msedr...0...1c.1.64.hp..1.8.650.0.WcwDUy7nWsc
Because of the issue between Mac OS X and Windows I use a WDC NAS/Network Attached Storage connected to my Router, has no problem storing files copied from Mac OS X, Linux Mint or Windows even though it is formatted as NTFS. Mac doesn't have good native NTFS support and I haven't yet come across a worthwhile third-party app for it. For an External USB HDD I keep a 120GB FAT32 drive available.

Apparently, I erased the partition table so now I'm using Disk Drill to recover files.

Formatting a drive normally only writes the partition table - this is only one (or perhaps 2) tiny little file(s) at the beginning and end of the drive.

If you want to share Mac and Windows use NTFS. HFS+ is only readable using Paragon or Bootcamp drivers (and both break Windows 10). FAT32 is OK but not really designed for large disks. exFAT is terrible and will loose your data for you (in my experience).

Or just stick it all on a SAN.