South Bridge: Intel ICH7
4 x SATA 3Gb/s connectors supporting up to 4 SATA 3Gb/s devices
The ICH7 does not support AHCI. It only supports IDE mode.
I don't know what OS you are attempting to use or what SSD you have. Your SSD might not support IDE mode.
Your Intel G31 Chipset is a 2007 model. I would recommend moving away from such obsolete hardware.