> 1. The installer is not in English, even though the home page is.

This is a bug in NSIS rarely seen on non-English versions of Windows.
We've never been able to track it down, but it likely has something to
do with the way NSIS discovers the system's language.
I've been to the NSIS homepage and just realized that the cream 0.39 installer is compiled with NSIS 2.18, whereas the current version of NSIS is 2.34. Perhaps you should try to compile the installer with that one.

> 2. Apparantly, the options in the installer don't work. Even when I
> choose the "Full" option, some installation components (the desktop
> icon, namely) are not selected.

I just reviewed all these and the fixes should be in the most recent
installer to be uploaded in another hour or two.
Where? I couldn't find the installer, not even in the "Download > Browse All Files" section...do you mean the "cream 0.40 alpha" one? That was just a zip file, though...

> 3. When I open a file through "Edit with Cream/Vim", and open yet
> another file with the same options, Vim alerts me that "a swap file
> has been found", even though there wasn't one. When I choose "edit
> anyway", the file that I had been editing is *appended* to the newly
> opened file, and the previous one is left *blank*.

Vim makes this alert only if another session is currently editing the
file. Could you have a Vim and a Cream session with the same file
open? Perhaps another user?
I'll make this clear by giving you an example:
  1. I am using Microsoft Windows XP on my laptop, which has no other users logged on.
  2. I have several source code files in a folder, which I will call "C:\SomeDir\Dir2\file1.cpp" and "C:\SomeDir\Dir2\file2.cpp", etc.
  3. I use Windows Explorer to browse to "C:\SomeDir\Dir2\".
  4. I right-click on file1.cpp and choose "Edit with Cream/Vim". Cream opens up nicely.
  5. After some editing, I right-click on file2.cpp and choose "Edit with Cream/Vim". Cream/Vim tries to open the file in the existing session, then produces the mentioned error.

If I set the Windows Explorer options to view hidden and system files, between the steps 4 and 5 I see only file1.cpp.swp and no file2.cpp.swp, which Cream/Vim claims there is. Is it a problem with Vim itself or clashing script problems with Cream?