I have a small suggestion.  make an ISO file in addition to your downloadable EXE that includes an autorun file.  the autorun.inf file should be in the root directory of the ISO file along with the exe and should contain the following:

[autorun]
OPEN=OOo_3.0.1_090128_Win32Intel_install.exe


what this does is make a cd that automatically runs your program when it is inserted into the drive (windows).

try out http://sf.net/projects/cdrtfe which includes a decent build of windows version of mkisofs.  If you want to make ISO's larger than 4GiB you will have to use iso level 3, so I use it by default anyway.  graft points is multisession. you will need to copy the cygwin directory into the cdrtools directory to make the progfram work from a command-line.

make a .cmd batch file out of this:
"c:/program files/cdrtfe/tools/cdrtools/mkisofs.EXE" -o OxygenOfficePro3.0.1.3.iso -iso-level 3 -joliet -rational-rock -joliet-long -allow-multidot -allow-leading-dots -graft-points -volid "OxygenOffice3013" -appid "Oxygen Office Professional 3.0.1.3, includes templates and plugins and OpenOffice 3.0.1 installation" -preparer "Joe Shmo jshmo@nowhere.com" -publisher "http://sf.net/projects/ooop" c:\projects\OxygenOffice-3.0.1.3\release\win
 
Jim Michaels
jmichae3@yahoo.com
http://JesusnJim.com