hey guys im new to here and i love backtrack for pen testing..
i want to install backtrack to my HD but i still want to use windows 7 that is my default os on my pc
so the problem is im scard if i click erase and use the entire disk

is that option will delete my windows 7

and when i try to install it using the other option it tells me

erron 28 < this error is when i dont have space on device / partitions

so how can i increase the size of the partitioners ?

and im using usb live install method

so if there is anyway to install backtrack 5 r13 to my HD (meaning like how i use windows normally )
please tell me guys im tired of searching