it wouldn't work if the chipset and other motherboard items are too different.
for me, I was able to move from a soyo k7vta motherboard to a asus A*V with out reinstalling windows. it just booted up and detected the drivers needed.
but when I upgraded my old 533MHz system that I used as a server, to a 2.1GHz amd athlon xp 2400+, windows bluescreened on bootup and it had to reinstall
it most likely work work if you install with your desktop and use it in your laptop, but you can try, if you want, you may get lucks, since from the looks of things, theres nothing currently important on the laptop drive