I keep hearing a weird clicking noise from inside my computer when browsing. Since my Firefox is installed on my Seagate secondary drive I want to say the noise is coming from there since it only seems to happen when loading web pages (caching info) and such. Is this possible? Is this a defect? I've only had this computer a few hours so I can't really offer any real tests.
If it is kind of a hollow clicking sound and there might even be a bit of a faint high pitch whine preceding it, then that would be the infamous click of death that HDDs sometimes suffer from. Doesn't matter if a drive is fresh out of the anti-static bag from the factory or 10 years old, this issue can strike any time, so time to replace the drive. If it's still new, you should be able to RMA it.
Seatools SHOULD tell you if the drive is bad, but there is always a possibility that if what you have is really the click of death it may say the drive is fine if it happens to behave while you're testing.
As for your other question. So long as you do not try and boot any OS that may be installed on that drive, it should be fine.