So, my friend gave me his old 500GB HDD because he bought a new 2TB SSD for his PC. Then I realised my motherboard's SATA ports were all full (except for one because of my M.2 SSD). And all my USB ports were occupied. All I have left is 1 SATA express and 1 PCI slot left. Anyone has an idea how to get more SATA ports? And I didn't find any SATA express to SATA adapters.