Boot camp: "The startup disk cannot be partitioned or restored to a single partition"

Hey guys,
Would really appreciate some help on this!
I'm looking to setup a windows partition on my iMac so that i can play a specific game that just came out recently. (NBA 2k15 - it's the only game i play).
I used to have a partition for windows on this computer until my HD crashed and i had to take it to the Apple Hospital. When i restored my backed up Time Machine mac clone, BootCamp would no longer let me partition anything for some reason.

What happens is: I load up Boot Camp as usual, push Continue passed the Introduction screen, then i get a msg pop up that says:

The startup disk cannot be partitioned or restored to a single partition.

The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows.

Click to expand...

Then i push Ok and it goes back to the BootCamp introduction screen. I.e. i can't get passed this msg.
I looked in Disk Utility and of course my internal HD already is Mac OS Extended (Journaled) so i have no idea why it isn't being recognised as one partition.

What do i have to do to be able to install windows on this computer without having to format my entire Mac? I have a 1TB external HD that i can backup my mac with using Time Machine, but i really need the exact clone of what i have right now.
Or is there any other way to play 64bit windows7 games on mac?

Some specs:
- Boot Camp Assistant version is 3.0.1
- Mac OSX 10.6.2 (yeah i guess i'm old school now)
- 2.66 GHz Intel Core i5, 4 GB RAM
- I have no other partitions currently, just my current mac one

Any questions just ask. I would love to resolve this tonight.

FYI: Solved this via help from the apple forums. If anyone ever finds this via google and needs help, here's the thread that did it for me: https://discussions.apple.com/thread/6586339