Sorry for not responding sooner... I've not been watching threads other than the main one in the Freeware Announcements area. If you have other questions you will probably get a much faster response by posting there.
The path to IrfanView can be easily discovered by right-clicking its icon on the desktop and selecting "Properties" from the context menu. You will see a dialog that shows the path to the executable. For example under Windows XP this is typically "C:\Program Files\IrfanView\i_view32.exe". Under Vista or Win7 64-bit you will typically see "C:\Program Files (x86)\IrfanView\i_view32.exe".
However... I am about to release Version 1.1.0, which no longer requires IrfanView. This is scheduled to occur on Friday or Saturday (11/25 or 11/26) assuming all goes well with the testing process.