There's Win4Lin and VMWare if you want to propiatarily run Windows on top of Linux.
Then there's Bochs, i couldn't get it working last time for me though.
http://bochs.sourceforge.net/
And Plex86
http://plex86.sourceforge.net/
Again, I havn't tried any of these yet.
I've been sticking with wine, have you tried wine yet?