|X64 and X86 aren't two distinctive terms. X86 means compliance with 32-bit architecture of the 80386 cpu and up. X64 means the cpu has 64-bit capabilities. A cpu can be both x64 and x86. Here's some additional info:|
What you probably want to know is if your cpu is 64 bit. Likely there'll be diagnostic software that could tell you. In general I think Intel's core 2 duo cpus and AMD's K8 line are all x64. But you should be able to just google your cpu number and find out that way.