Re: Battlefield 1942 disc 2 data3
Is it a DVD-ROM edition of the game? (They made one?) Have you tried pressing "Ok"? It should automatically find a "disc 2" folder on the DVD-ROM if that is the case, otherwise you would have to find the Disc 2 folder on the DVD.
It is likely that, being an old disc, data3 has become corrupt and is unreadable. Because of this you will likely have to buy a new copy of the game, unless a "CD/DVD" cleaner and "Laser Lens" cleaner fix the problem.
If you have a fast enough internet connection, BF1942 is available for free on Origin.