Are you going to make 64bit release of RadASM2?
Looking at the "code" in the attachment, I seriously doubt it myself.
The code itself is a mish-mash of macros and equates that don't have anything to do with the body of the "code" (if you can find it.)
Looks more like a lot of copy/paste and does not display a message box, since that code is commeted out (and in the wrong place anyway) . Not sure exactly WHAT that code is trying to do.

I didnt even bother to try and assemble that, or even parse out the actual "code" bits, nevermind trying to find anything resembling a header.
Not sure why this is here, since there is no rap file so it probably was/is not a radasm project
Just my humble opinions of course. And I had to reinstall Win 7 64 bit from an image just to look at that.

Edit to add:
No!
First step of Win64.
No, the first step in any programming language is a simple "Hello World" in a console application.
Or if you are adventurous, a "Hello World" message box.
If you need help, you can always ask on this forum.