Questions about Seagate backup drives

I bought a Seagate backup plus slim 1 TB drive some time ago to use as a Time Machine backup. It is working fine. When I set it up I did not have to sign up (give my name and email address etc.).
My girlfriend bought exactly the same one and we are having a lot of difficulty in getting it set up to use on her computer. Her computer specs are as below:

MacBook Air (11 inch, early 2015)
OSX 10.10.5 Yosemite
1.6 GHz Intel Core i5
4 GB 1600 MHz DDR3 memory
120 GB Flash Storage hard drive

She bought it to use as an external hard drive to store photos on. The first step in the setup process is to sign up (and receive free cloud storage). She does not want to sign up or use cloud storage (just wants to use it as an external hard drive). We skip that step and go through the rest of the process. But she can't write to the Seagate drive? We also have Fujitsu and Hitachi external hard drives and all we had to do was plug them in and start copying stuff to them. Why does Seagate have to be so difficult to get along with?
Thanks for any help
Dan

Well first questions - was it formatted Mac OS Extnded (Journaled) in Disk Utility? If so after formatting it is necessary to go into Partioning > Options and ensure GUID format is selected. Do not run any of the usual included programs which are for PC's only.

Why does Seagate have to be so difficult to get along with?

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As Harry pointed out in the previous reply, Seagate drives like most other drives are factory formatted to be used with Windows. Which means the Seagate drive is formatted to NTFS. You need to re-format the drive in order for it to be used with your friend's MacBook Air. As Harry stated, it needs to be formatted to OS X Extended Journaled using the GUID scheme. That's done using the Disk Utility program her Mac comes with.

Thank you very much for the quick responses, harryb2448 and chsag. Very simple and it worked. Makes me feel like a dumby. I bought my Seagate from an Apple store and when I plugged it in the message box asking me if I wanted to use it as a backup for Time Machine was the first thing that popped up. My girlfriend bought hers from Staples.
Thanks
Dan

Our pleasure mate. And remember there are no dumb questions ~ only dumb answers sometimes!!!!!

harryb2448 said:

Our pleasure mate. And remember there are no dumb questions ~ only dumb answers sometimes!!!!!

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Harry - great advice! No question is dumb, especially when new to computers - always ask before doing, if unsure of the action.

And as to answers, always think, review, and check the information given - a lot of harm can be done providing hasty advice that may not be accurate or potentially dangerous! Dave
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