One problem you have is that you're running a 64-bit computer, especially XP.
It is normally determined by what computer the person used to code the hack, and what they made it available for.
I'm running x86 version of XP, but I have Windows 7 x64 partitioned on my HDD as well.
Is anyone else running this OS (Windows XP 64-bit) getting this error?
EDIT:
Before running the injector or the hack, try opening up Properties and change the compatibility settings.