I use Installshield Express to create some Windows installers. Problem is it does not allow the direct creation of a packaged MSI file. You can get an MSI but its output is a folder structure, the applications files are not packaged within the MSI itself.
Luckily I found this solution on StackTrace
For the lazy you basiclly do this, extact the MSI out of the setup.exe that the SingleImage format generates.
setup.exe /s /x /b"C:FolderInWhichMSIWillBeExtracted" /v"/qn"