Also, one other thing you should check before you go further: Looking closer at your system configuration of the Virtual machine, it seems like it's got two CD-ROM drives configured. Don't know how that happened. Just in case that's the problem, make sure it's just one CD-ROM drive in the device configuration, and then see if it'll boot from the disk.

If not, then double check that the pirated CD is bootable or not. The way to tell if that, is to try to boot your real computer from it. Obviously don't follow through with the installation, just go far enough to see if the real computer successfully boots off of that CD, then turn the computer off before going through with the installation.

Assuming that the problem is indeed a non-bootable CD, then, one thing you might be able to do, is create a bootable Windows 7 installer ISO file, and then simply tell VirtualBox to use that ISO file instead of using the real CD drive. For example this way is one possible way:

http://www.makeuseof.com/tag/make-bootable-usb-cd-dvd-install-windows-using-iso-file/

I've never tried the method outlined there, but from the looks of it, one advantage to it is that it gets you an actual Microsoft installation ISO, rather than just some pirated disc. This assumes that your Windows 7 product key (possibly found on that pirated disc) is valid somehow. :-)