Is anyone else having problems playing either of the first two games in full screen? When I start the first one, for example, it shows the little "loading" floppy disc, and if I click a few times, the Sierra fanfare and eventually the QFG theme plays, but the game never goes off of the little floppy disc. If I press alt+tab a couple times, the game plays fine in a window, put I can't get it to return to full screen, though I suspect that's more of a Dos-Box illiteracy issue than a problem with the game.

QFG2 is the same, except it has a little cursor instead of the floppy disc.

While I cannot help you with the freezing issue, but you can switch between windowed mode and fullscreen by pressing ALT+ENTER.