(re: Internal PC Speaker sound)
There is an emulator to try called Nagi, which will play all the old AGI style Sierra adventures perfectly. It even plays the games with the three channel tandy sound and some of the digital effects that were in them. This makes them sound far better than the PC speaker. DOSBox will run games but only with 1 channel PC speaker sound and it will struggle on an old Win 98 machine (if it is an old machine).