One suggestion to your problem: Virtual machines. :)
Windows 8 will recognize your windows 7 installation but won't recognize the ubuntu installation. It's best to first install all of your windows installations from old to new. for example: first windows XP, second windows 7 and then windows 8 and afterwards your linux. Linux always recognizes the windows os and will install over or next to it. That's up to you.
But, and therefore I suggested it, there's another option: virtual machines. I have a windows 7 running, with several (7 to be exact) virtual machines. And I have got to say, it works for me. I can access all my linux installations inside windows. For example: I can have windows running with 2 virtual linux machines. And by installing them virtually I can test connecting from windows to linux. I can install virtual servers (Samba and Apache) and test how they work with windows. If something goes wrong with one linux machine I can always go back to a snapshot I made, without reinstalling the whole thing.
There are several programs for doing this, like Virtualbox and VMware (these are the best known.) Setting up a virtual machine is very easy and it installs faster then a normal installation. You can add as many network cards as you like, you can choose how much memory you want to dedicate to each machine, you can set up the size of the HDD,... Virtual machines are very flexible, and that's why I think it would be a great option in this case.
But that's just my suggestion. Hope I could help you.:)