Hi Imnope1,
It seems you have a broadcom wireless card, and a problem almost identical to this:
http://forum.backbox.org/general-support/problema-durante-l%27installazione/msg5561/#msg5561Don't know if you understand the italian language (google translate could provide you an idea of the discussion), but basically, during the installation, there is an issue with your wireless card.
However be sure, for all the methods listed, to uncheck the box relative to the download of updates and packets at the beginning of the installation process, avoiding to have your wireless card wrongly detected again, due to packets download.
If you can disable the wireless via BIOS configuration panel, than the OS should not detect it and never load its modules. Than, once the installation is finished, you can bring your wireless card up and reinstall the packets you need to make it work. The user in the post i linked above needed the b43_legacy drivers, so, if this is your case too, you can reinstall the right driver after the installation.
You can also try
this, removing your wireless packets, or blacklisting them, on a persistent -persistent- live usb.
The user solved by blacklisting the b43 module, which generated the conflict, as boot parameter in the grub (i think editing the backbox entry at the line starting with "
linux") adding:
b43.blacklist=yes
then proceeded booting the BackBox kernel just modified and installing it, and in the end reinstalled the right drivers after the reboot.
This methods worked for him, so you can try this first. Maybe try to contact him in private if you need more details, and in the case you solve you could post the solution here...
Should not be an unsolvable problem

Good luck!
Enjoy BackBox.