If you have more than 1 disk in your system, and you have RAID+AHCI set, then you likely need to jump into the raid controller BIOS at boot time (by pressing "CTRL C" if i recall correctly) and define a virtual disk or VD (which can wipe existing data so be warned).
Then when windows install loads, you will see the virtual disk that you have create earlier and can thus select this VD for the install to continue. This assumes the install media has the (chipset) raid drivers which i think is the case.
If the install disk does not have the required (chipset) raid drivers, then you may need to place them on a usb drive and point the install to it using F8, at which point you will see your VD and can continue with the install.
If it all sounds like too much, you can remove all but one HDD and then RAID function will not be relevant as it will fall back to simple AHCI. If you still don't see the lone HDD, try and add the chipset drivers using the F8 method.
I had similar issues a while ago on my Z210 and solved it by using default BIOS firmware settings, then created a VD and lastly placed Intels RST driver, specifically the F8 driver on a USB and during the Windows install process pressed F* and pointed to the USB drive where the driver was seen and loaded at which time my VD was visable so all could continue.