What is you drive formatted to? You mentioned looking at it through Disk Utility, so I'm assuming you're trying to see it with your Mac. Mac's can only Read/Write to HFS/HFS+ (Mac OS Extended) and FAT32 formatted drives. The typical Windows NTFS format can be read by mac, but not written to.
Conversely, PC's can Read/Write to FAT32 and NTFS drives, but can't even see HFS/HFS+ drives. The only drive format compatible between the two is FAT32, but that's slightly antiquated at this point.