lol I do the same

@devendra just check that these file transfers are not considered as downloads from the internet, of course if you are on a Unlimited plan it does not matter
Ummm no local PC to PC transfer through your
router's local network will definitely not be counted in your usage.
I have tested it on my MTNL connection.
---------- Post added at 06:09 PM ---------- Previous post was at 06:03 PM ----------
Also the speed of wireless file transfer will depend on the router you have.
28mbitsps -- Around 1.8mBytesps -- (current router MTNL gives out)
56mbps -- Around 3.2mBps (router given out about 2-3 years ago by mtnl)
If you want higher than that you will have to buy your own router (probably one N based). Remember your other PC wifi must support N based network too for greater speed.