With latest systems, it comes more and more complicated to get a running DOS-system. An alternative are emulators. There are two DOS emulators. Both can run a couple of old Games and Demos, it's worth trying out both.
DOSEMU is no real emulator, as it doesn't emulate the CPU instructions, it only gives you a way to run a real DOS in a Linux System.
As it runs CPU instructions directly, it only works on x86 CPUs.
DOSBox is a real emulator, thus running on a couple of platforms and probably the better choice for the future.
If you are playing old LucasArts Games, there's a better alternative than using DOS emulators: ScummVM implements the engine of the well
known games like Maniac Mansion, Zak McKracken or Monkey Island.