Unfortunately for you you've got a stock v7 so you'll need SOME form of hardware but that's where you have a choice of how much to spend.
I
made my own probe (3 posts down) which cost practically nothing to make and also use an old Xbox to power.
Alternatively you can go down the commercial CK3 w/probe route which will cost you about $40/$50 (complete guesswork here). For a one off I'd go down the homemade route but it all depends on how confident you are with a soldering iron etc.
Also for the OP, since you are new to this it seems, follow his advice quoted and also be careful you do not plug in your drive power cable upside down. You can check its plugged in right because there are notches on the sides and top of the cable that fit nicely into the plug. Make sure you plug it back in right before you turn on the xbox or bad things will happen. I know its common sense thing that people should probably know, but you'd be surprised how often this happens.