http://jhunix.hcf.jhu.edu/~bfrazer1/gk/
that shows you how to play GK1 on XP.
I just played through the entire game through dosbox as described in the link, and it works great... saved games no problem.
Just wanted to add that i fell in love with GK1. i hadn't played any adventure games in years, and then played Longest Journey a couple of weeks ago, and was very disappointed... was almost turned off from the genre. And then i bought GK1 and it changed everything!