My Passport Suddenly Shows up as "Local Disk E:"

Hello, I purchased a WD My Passport Essential SE 1TB a few weeks ago. I formatted the Drive to FAT32 for certain reasons and the Drive has been working wonderfully… until today. The drive had been working great today. Until I plugged it into my PC. The Drive usually shows up as a removable "My Passport (*drive letter*) but now it is showing up as a “Local Disk (drive letter)” If I chose to click on the drive it says “this folder is empty” Even though the properties say that over 40GB has been used "which is accurate. What must I do? I now have no access to my precious files and I am very upset. Thank you. -Tyler

What OS are you running?

Happens on all my computers regardless. Windows 7 starter and Windows XP.