OK here's what happened.
You installed the OS with both drives connected.
Mistakenly, the OS got installed on the HDD. That can be fixed, but if you want to leave it as is, no problem.
On the SSD, you see a 350mb System Reserved partition. That is your boot info. That is normal and expected. When you install Win 7 or 8 with more than one drive connected, that partition ends up on the other drive.
The reason you can't install to the rest of the SSD, is because that partition is simply not formatted yet.
That 223.23 space...right click on it, Format that partition, and give it a drive letter.
Then you can install stuff to it as desired.
Leave that 350mb space alone. It is required.