I've run both GNU emacs and Xemacs on windows. I used to use it as my primary editor, email client etc, but not it's "just" an editor.
When I recently reinstalled to Vista I installed the latest GNU version. It works fine. So does Xemacs, but it does look like GNU have got their sh*t together so Xemacs isn't as compelling anymore.
I've encountered this problem, and discovered the fault (at least in my case) to be the existence of c:\site-lisp\site-start.el, a file that was created when EmacsW32 was installed, and which was not removed when I uninstalled it. (Vanilla GNU Emacs for Windows has c:\site-lisp in its load-path, and will try to load this file, which somehow winds up triggering that error.)
Solution: removing that whole directory (c:\site-lisp) worked for me, but you should just be able to remove the site-start.el file.
If You Mean Emacs as Latex Editor for Windows 7.
Emacs4LS (Emacs 4 Latex Support under Windows 7) for newcomer for Emacs.
http://chunqishi.github.io/emacs4ls/