Your NAS is connected directly to the gigabit ethernet port of your Windows7 desktop PC - presumably directly means a network cable from the PC, directly to the NAS, no hub, no switch, no router, no access point - network #1
You haven't told us how the Windows7 laptop connects to the desktop, but I suspect it's wirelessly - a typical home network might have a wireless router connecting to the internet and then several PCs that connect wirelessly to share the internet - network #2.
There's no link between network #1 & network #2, at least none that you have mentioned - so there is no communication path between the two, unless you build one using the PC as a router or bridge - it can be done - but it would probably be a lot easier to connect the NAS to the router that's in network #2, assuming that there is one.