I assume you have at least one drive that is being recognized - since you can boot Windows?
Since you refuse to state what easy solutions you've already tried, I'll just list the obvious ones:
Have you connected SATA power to the new HDDs?
If you have a modular PSU, check that the SATA power cable for the new HDDs is connected to the correct connector.
Have you tried different SATA connectors on the motherboard? Which ones?
Have you checked SATA settings in BIOS? (Whether any ports are disabled.)
Have you double-checked that all connectors are properly seated? Power connectors should make a small "snap".