A:
I am using the Seagate - Barracuda 3TB Internal Serial ATA Hard Drive for Desktops with Windows-8. There has been absolutely no issue.
Once you've installed the thing, you will have to use the Windows hard-disc manager program to tell the system how you want it use the disc. I don't remember whether Seagate's instructions are particularly clear or not as I didn't need them.
The machine I bought it for is an HP desktop that came with Windows-8, and it came with a similar Seagate Barracuda drive (but only 1 TB) for its system disc, so there is no question that this family of discs is appropriate for Windows-8.