My copy of mass effect 2 came though the door this morning, however, since I only got mass effect 1 last weekend and I haven't finished it yet ME2 is still sitting quietly on my shelf, I'm current at the citadel attack however since I've not even touched disk 2 yet I'm completely unsure as to how far though the game I really am.
Mass Effect only has one disc... so... not sure what you mean there.
In fact, Mass Effect International Version has two discs. The second disc only holds additional languages besides english.
I wondered exactly the same question a few weeks ago. I installed it in english, never asked the second disc
My girlfriend recently installed it in french, and it needed the second DVD through the initial install procedure ...
Besides just insert it & have a look at the files in there, it's pretty self-explanatory..
French does sound a bit weird by the way with Nihlus voice not being transformed from a normal human voice for example and generally things going a bit too far in the full translation mode (C-Sec renamed for example to SSC or something along this line ... :doh )
edit: bah.. just saw that the question was already answered a few post ago :hide