關於開啟assembly code[20點]

Try xvi32. It is a freeware hex editor. It allows you to open, create and edit all files in binary/hex mode. You can download it from the following website:
http://www.chmaas.handshake.de/delphi/freeware/xvi32/xvi32.htm

This web page also includes screenshots and introduction section. You may want to check them out first (as a learning tool).

However, from your question, you may want a disassembler instead. The differences between an editor and a disassembler is: an editor will allow you to editor and view binary files (exe files) but it will not show you the assembly code whereas a disassembler will show you the assembly code that reverse engineer from the exe file.

If you need a disassembler, you can try the following:

http://www.geocities.com/~sangcho/disasm.html

First of all, most of the programmers wont write codes directly in assembly. They'll first write the code in a common programming language (say C, C++, Java), then compile them into assembly code. Once compiled into assembly code, while you can reverse the assembly code (e.g. using OllyDbg, W32Dasm), it won't be easy to reverse back to original language (like C).

An exception is that the program is created under .NET Framework, where the program is compiled into IL. In this case, there will be software to get the code. (e.g. .NET Reflector)