So what happened before was, my Seagate was corrupted. Then I fixed it by checking for errors and fixing the errors. And thankfully, it worked. I can open it properly. But when I tried to copy files, it was so slow so I safely removed it and tried it with my mom's MacBook Pro. When I plugged it in the MacBook, it appears in the Desktop but when I opened it, the files won't show and it was just reading and waiting forever. So I just tried to eject it. But it won't eject so I just disconnected it 'cause I figure it won't damage anything since I didn't open anything. So I went to my laptop running Windows 7 and I plugged the HDD again. This time it doesn't show up in My Computer and anywhere for that matter. I can see it just a few minutes before and then suddenly I can't.
I would really appreciate if anyone can help me with this. I got important files in that HDD. Thanks in advance!