I have figured out the issue. You have to use default encoding for both exe to string and back:
Well this post is closed, but thanks for looking! Maybe this will teach somebody something.

My issue is when I read from an existing executable and convert it to string and back to executable windows says it is not a recognized 32 bit or 64 bit application? The code below is real code I have rewritten many times but to no avail. If I leave out the part where I convert the bytes to string and just copy the binary and create a new exe with the binary the program works. But the whole concept of string converting back to valid binary has me...