I am running windows xp sp3, but the 32 bit version (not 64 bit), so should be ok. Perhaps a simple in-game test can be suggested to ensure that the changes have taken effect.
so I finished installation process now, it seems to be working ok. I installed bgfixpack and bgt mod and also xpmod. I did not install bgt music mod or widescreen mod. The bgt mod had to be installed to the 'baldur's gate' folder directory on the 'C' drive, because it would not install to the 'BGII - SoA' directory. I used 'no-cd patch' on 'BGMain.exe' straight after the initial clean installation of the game.
had to restart pc afterwards as it had become very sluggish (despite having quad core processor and 4gb ram)