And what's important, we'll tell you how to recover data from the hard drive after making it work again. Then, we'll cover the methods to fix it as well. However, if it contains lots of important data, how can you recover data from it? In this article, we'll tell you why is your Seagate external hard drive not showing up or detected. If you don't have any important data on the hard drive, you can just format it easily. Consequently, the disk itself and the folders and files saved on it become unapproachable and unluckily this is a common problem with Seagate drives. Occasionally, when you plug in any Seagate external hard drive to PC, it may not show up or be detected by your PC.