What display drivers did you use for XP.
If you had to mod the inf file to install them (i.e. using newer desktop drivers with your 9700GT card) then Blu-Ray will not play as they are no longer digitally signed.
I have no idea about setting region codes for Blu-Ray as I use AnyDVD to strip region codes from all my DVD’s and Blu-Ray discs, best bit of software I have ever used.
BTW, the G71V comes with Home Premium and not Ultimate as I am currently using one to type this.