One supposes it doesn't count as double posting when you do it in English and otherwise, but don't do it again I think.
On with the show: First, if you are a Macbook owner, you can probably afford a copy of VMware Fusion 2 - which I recommend. There is no actual good idea to run BT as the main OS on a Macbook - OS X works better and, to be perfectly honest, the wifi chipset is generally a broadcom and thus unhelpful when you try to crack your neighbours network - so you need a USB wifi adaptor anyway.
If you still insist on installing it to the HDD without a Fusion option, we're going to need a bit more information - specifically what bootloader did you select, what formatting of the HDD did you choose and such.
If you cheated and split the HDD into [OSX]+[32GB_Windows] using bootcamp, you might actually be able to install BT that way, but I've never tried it and, well, see my first point.
If you are going to use something, look at Bootpicker. It only works with 1 OS X install, 1 Linux install and 1 Windows install (or mixes of the singulars), but it's a very simple tool to use - install it as a pref pane into OS X.