Though I've used Ubuntu for a few years, I'm new to installation. Previously I had help and now I'm doing it alone (moved across the world).

Windows 8.1 came preinstalled on my new laptop (Toshiba Satellite C70-A-17C - Core i5, 8 GB RAM, 750 GB HDD). I have already followed a few steps I found online to prepare for a dual install (with Ubuntu 14.04).

I backed up Windows, created a bootable Ubuntu USB and DVD (just in case one didn't work), turned off fast boot and secure boot, and shrunk C:/. The new unallocated drive portion is 292.97 GB.

After shrinking C:/, I restarted Windows a couple of times to make sure everything was working fine (it is). I then attempted to install with the Ubuntu live USB. However, the Ubuntu installer doesn't see that Windows 8.1 is already installed. I don't understand, and don't want to mess with Ubuntu partitioning when I don't know where the partitions will be created. My concern is that, if I go further with the installation process, Windows might be overwritten or compromised in some way.

I then tried to reboot using the Ubuntu live DVD, thinking I might get a different result. However, I can't figure out how to make the laptop boot from the CD drive. I went into the BIOS and found no option there, either.

Any help is very appreciated!

EDIT:

Looks like I can't link directly to each photo.
Here is my album of screenshots:
http://imgur.com/a/zChCo

1. Here you can see that there's no option to boot from CD drive, only USB.
2. Everything looks okay so far.
3. I don't understand this. Ubuntu has not yet been installed. Unmounting partitions? (I chose 'no'.)
4. Even though the laptop came pre-installed with Windows 8.1, the Ubuntu USB installer can't see it. I chose 'something else'.
5. I need to pick and format partitions. I scrolled down and took a second shot to include all information. Completely lost and cancelled installation.