Cakewalk Express was free on a PC cover disk in the UK about 4 years ago, so maybe thats out there somewhere? It was very cut-down, however, and I dont think it used instrument files so I suspect this might be a stopper!

Also sound cards using Yamaha chipsets (YMF 7x4) sometimes bundle "XGWorks Lite" which is not too bad. I am talking about budget soundcards here (made by e.g. AOpen) NOT the yamaha SW1000XG!