First: be patient for my horrible English

I have the italian version of Baldur's Gate and i downloaded the following files:
DSotSC_v215
NTotSC_v170a
NTotSC_v171
I installed the following programs and patch
Baldur's Gate
- patch bgintl114315.exe
Tales of Sword Coast
- patch BGTalesIntl5512.exe
After that i installed DSotSC_v215
But when I try to install NTotSC_v170a ( --> i launch the file Setup-NTotSC.exe), i take a error that you can see on the screen:

Please, can someone help me?
More information:
- i have Windows XP
- the game is original: Baldur's Gate 5CD and ToSC 1CD
- the game work perfectly
Thanks for the help
