Arrive CDG at 7 AM Friday morning. Depart Orly at 1 PM same day. What is the best way to get there? I arrive via United into what i believe is Termninal 1 at CDG. My Air France flight departs from Terminal W at Orly.

Thanks for all of your help. I am finally on my way in less than 24 hours.

I'd say that the easiest way is to take the Air France bus, which stops outside the terminal. Your luggage gets stowed under the bus; so you don't have to deal with it yourself. You can buy a ticket out on the sidewalk at a kiosk.

Take the commuter train line (RER-B) marked "Direction Saint Rémy de Chevreuse" all the way to Antony, change there to the automatic rail VAL system to Orly airport. Costs €18.55, I think. You could also take the Air France Bus #3 directly to Orly. Costs €19, I think. If cost is not an object, you could take a cab or shuttle, but be prepared to pay a bunch more.

The RER from CDG to ORY is now 19.40€. The Air France Bus #3 is still only 19€, the driver will load your luggage for you, and the seats are much more comfortable than those of the RER.

Of course the RER has no chance of getting stuck in a traffic jam.

True kerouac but the bus does not come to a complete stop every couple of hundred meters, the bus will have comfortable seats, and there is no bus change (and luggage haul) at Antony. I like the bus, the view is better.