I tried to install it on a Windows XP x86 ( last time I was on a Windows 7 x64 ) and it is giving this error:
'twisted' package is not installed, pywallet web interface can't be launched

I also tried to install it manually ( the 'twisted' package ), but it is giving the same error.


And also, there is another set that can be useful:
%ProgramFiles%

Example:
On the english Windows, it is probably:
"c:\program files"
On the italian windows, it is:
"c:\programmi"
( I don't know on other languages )

On Windows 7 x64 there is also:
%ProgramFiles(x86)%
On the Windows XP  %ProgramFiles(x86)% doesn't exist

So this is another way to make it working on every architecture and every language.