windows 7 - SSD is detected under Win8 and in BIOS SATA Config but not in boot menu

I've got the following issue: My new SSD I put in my Asus N56VJ for the CD drive is detected and working under Win8. In the BIOS menu under SATA-Configuration it's listed as well.

But it is not listed as a bootable device. I only see my USB CD drive and two times the Windows Boot manager pointing to the same device (I guess my HDD).

Any ideas what I can do about it? BIOS is up-to-date.

I only play around in the BIOS because Windows Installer is telling me that I can't install Win7 on the SSD because it's not bootable and when I just try it I get an error on Bootup about a wrong/damaged startup file...

Edit:

When I try to install Windows 7 via Windows 8 (I open the CD), I get the following info when trying to select my SSD:

Windows cannot be installed on this hard drive. The partition is a microsoft reserved (msr) partition

Any ideas why or how I can fix this? Is this related to my issue?

Thanks!