There are multiple hacks to PC-DVD players.  Try 
a search on the web for "region free DVD".  
Alternately, try some of these websites

http://www.regionfreedvd.net/
http://www.wormintheapple.gr/macdvd/
http://regionhacks.datatestlab.com/

Some of the sites have good links as well.  It is 
possible to reset the number of times that a 
player will recognize a region code on a DVD.  
Hope this helps.

Craig