How do I reformat MY Passport (for PC) for use with both Mac and PC?

I recently purchased an Apple MacBook Air and also have a Dell laptop.  My Passport is serial number WXM1C5294201.

How do I re-format MY Passport for PC so that it will work  with Mac and PC?

Leave it formated for Windows and download NTFS-3G http://www.macupdate.com/app/mac/24481/ntfs-3g for the Mac. The other alternative if format it FAT32 the down side is the largest file it will handle is 4 gig.

Joe

I re-formatted the drive with my MacBook Air to exFAT, which I understand supercedes FAT32. However, when I plug MY Passport into my Dell laptop, I receive an error message “t the disk in drive F is not formatted. Do you want to format now?”

I’m selecting no because I do not want to lose data.

Why is it asking me to reformat?

That is my question.  Can I use a passport with both a PC and a Mac?  If so how?

Format the drive for Windows NTFS then download one of these in  post 6 http://community.wdc.com/t5/WD-Portable-Drives/unwritable-drive/td-p/435872

Joe