The much older games are they made compatible for xp/vista by the use of dosbox? or are the games programmed internally to work with upto date systems.

Anyone? :)

the games have either been editet by the GOG team to work on newer machines.
the GOG team has some of the finest programmers tied up in the basement working for food.
They also get great help from the dosbox team
so yea. all games work on xp and vista

Cheers Duck!