Windows 2000 Hard Drive Problem

Some info first…..I have a computer with 2 hard drives, running windows 2000 using a Fat 32 file system….
Recently I took out my 2nd hard drive to transfer data onto a Win98 SE machine. The transfer went fine but after putting my drive back in my machine, windows 2000 tells me that the drive needs to be formatted before I can use it….
Everything on the drive can be accessed if I boot into Dos….What do I need to do for windows to read the drive?