It can be forced to load in WMC but I believe that you need to get into registry hacks and such. MPC-HC is a better player anyhow because it is so easily configurable. madVR does not have 64bit and I don't know if it ever will but it runs just fine at 32 bit.
If you are not using MB for library management you can use Mikinho's Open With
WMC add in to force WMC to use MPC-HC as the player for certain file types.
This won't work for TV playback with tuners AFAIK.