problem with display Chinese GBK in Emacs

It seems to be an old question. But I met and failed to overcome it. I wish
somebody could give me a hand. 

My Emacs 21.2.1 (i386-msvc-nt5.1.2600) runs on WindowsXp. It can display Chinese GB2312 well. Since Chinese GBK includes Chinese GB2312, it can only display the part of GBK that matches GB2312. For example, "t" is displayed with "\235t". I have tried MULE-GBK package provided by Su Yong. I put the package in directory "/site-lisp", set the package path to load-path, and load the three files in .emacs. When I change the language environment and load a file containing GBK characters, nothing but lots of blank blocks is displaying. I wonder what is the problem and how to solve it.