I have the Seagate model SRD0SP0 500GB Backup drive. I can see the drive under device manager but cannot access the drive storage.
What does it do when you double click to open it? It could be corrupted or failing. My concern is if it needs to be formatted (corrupted file system) it will tell you. Probably failing.
Make sure that the drive is partitioned and formatted properly with the right filesystem for your OS