So basically, im installing a new motherbaord and cpu. this means i have to do a clean install of windows 7, but does it also download the drivers for the new hardware i installed?
If it manages to recognize your ethernet card then it should be able to do it, I've never tried that though, I always download all the required drivers before doing the fresh install, at least if it recognizes the network card you could download them on your own.
A way to check if this has been done, would be to go to your "device manager" hover over your desired hardware, right click it and press "update drivers". If there are new drivers then they will be found using the internet, and installed.
So basically, im installing a new motherbaord and cpu. this means i have to do a clean install of windows 7, but does it also download the drivers for the new hardware i installed?
Depends on what it is. In many cases you have to go to the vendor support site and re-install the drivers.