Today i will discuss about the difference between x86 and x64 processor.
x86 supports 32-bit and x64 supports 64-bit. Now a days many softwares come with both 32-bit and 64-bit compatibility. For example photoshop and windows 7 comes with 32-bit and 64-bit support.
The core 2 duo processor is x64 and that mean it is 64-bit and also backward compatible like supports 32-bit operating system also. When you install windows 7 it asks you whether you want 32-bit operating system or 64-bit operating system. So your choice will be 64-bit if your computer has processor of x64.