The software is radically different and they don't share almost any mutual hardware?
That's like asking why you can't put a ferrari engine in your motorcycle.
The drive may not even show as a boot option, and otherwise it would not have the correct software to load up. I believe the xb360 drives are a proprietary connector, they'd have to be a normal 2.5" sata hard drive to even get past the "putting it in" point.
If you reformat the drive and clear it, then you could load windows on it and boot, but that'd mean losing your xbox data and seems outside of your objective here.