Successfully installing an NSIS-created package requires some attention to the permissions of the person doing the installation onto their Windows machine.
A useful discussion of permission levels is here – http://forums.winamp.com/showthread.php?postid=2342257
If a user does not install SOFA Statistics with the appropriate permissions they might receive an error message like:
Error opening file for writing:
This may occur even if there is no folder called Program Files e.g. if they are installing onto a Swedish version of Windows. See http://forums.gforums.winamp.com/showthread.php?s=8a0906800e16ffd51be2d2fda1a23c4c&threadid=306563.
If it is necessary to check if a user is installing with administrator permissions, the following may be useful – http://nsis.sourceforge.net/Simple_tutorials.