I got it to run on Vista 64-bit, using Firefox. I don't think I have DosBOx.
I, well, after reading this thread, was really desperate to play a more updated version of the game. I downloaded a free trial OT 5 onto my new computer (which has Vista) and when that didn't work (it kept saying it couldn't find the file oregon.dat), I tried to re-download it on my old computer, since I downloaded and played it already about a year ago. But somehow the trial version knew I'd already played it on that computer (even though I'd uninstalled the old trial version) and just kept saying the trial had run out.
Sooooo, out of desperation (I REALLY was craving OT) I went to Target and bought the game for $20. It still wouldn't run on my new computer but I installed it and played it on my old one. Twice

Anyone got any ideas to help it run on my new computer? It said on the back of the box that it should run in Vista if you had enough RAM, which I definitely do.
Anyway, that's twice in the past two weeks that Adisc has prompted me to stimulate the economy. The first was the root beer thread.