I have a W7 x64 PC but I aware about compatibility when the final application will be installed in another PC.
Does automatically run on any Windows PC? What I should take in account to improve compatibility?
Yes, you can compile x86, x64 or Any CPU applications. You can also run any of these on your x64 machine.
If you compile an x64 application, this can only be run on an x64 machine. That is the only restriction.
Note that if you are using an assembly that has been compiled for a specific architecture, your application needs to use the same architecture to avoid errors when running on another machine.