here is what i have:

Windows Vista Ultimate

Intel Core 2 Quad Q6600
Northbridge: Intel ID2E20 rev 03
Southbridge: Intel ID3A16 rev 00
system manufacturer: Gigabyte Technology
Mainboard Model: EP45-UD3P

Video Card: ATI Radeon HD 2900XT

i have an external hard drive that i am willing to format if its needed. my plan was to dual boot vista and OS X. i have 1 HHD that i have divided into 2 partitions (from what i understand, thats what you need). is it possible to use a usb HHD rather than a flash drive? and if so how?

being that i have no access to a mac at all, is it possible to complete all of this through vista?