Same motherboard w/ extra RAM slots?

Hey everyone,
I have an HP computer I recently upgraded. I found while searching for a manual of this motherboard that the same exact motherboard exist with extra slots for ram (the motherboard is asus M2N68-LA (Narra5). Here is the motherboard I have now:
http://i01.i.aliimg.com/wsphoto/v0/551724027_1/For-HP-M...

Here is one I found on ebay that's a cooler color with extra RAM ports:
http://i.ebayimg.com/00/s/NDgzWDUxMA==/$(KGrHqFHJ!sE9BV0EYNBBPRmgvoSzw~~60_3.JPG

Both of these are supposedly EXACTLY the same as far as the basic components and the name/model of the motherboard (M2N68-LA (Narra5)).

Here's my question. If I bought the motherboard with the two extra RAM slots, would I have to reinstall windows? I always heard if you changed motherboards you would have to install new Windows like a new comp, but this motherboard is the same except the extra RAM slots.

This motherboard sells as cheap as 50 bucks, I can get 4GB of ddr2 ram under 40 as well so I could get a nice upgrade in ram if it would b e possible. Does anyone know if I could just switch motherboards to that other one or would I have to redo Windows with it? I just don't want to have to tinker with installing windows/all my huge games programs again it takes forever!