Thinking about installing LL on my main pc but need some advice.

[Moltke]

I do want to install it side by side my windows but it doesn't seem to see that windows is installed in the live boot disk.

If you noticed, in the desktop there's at least one device that shows as not mounted, that should be your windows partition. It seems to me that you haven't used Linux before, right? In live mode you won't see but Linux only since your pc's booting from the install media being this a USB or DVD. I strongly suggest you install virtualbox, create a VM and try the dual boot in there, that way you'll learn what to do and how to so when you are confident enough to proceed with the dual boot in your real pc you'll have most things covered. I've done that in the past and it've saved me time and effort. That's my advice. If you need guidance on how to create and manage a virtual machine feel free to ask.