packaging images /backgrounds

I have a program here with source files and excecutable only 1.5Mb but there are 4.5 Mb of graphics in a couple of files that go with it, is there any way of packing these in some kind of other filetype or something? i mean what happens in games with masses of graphics, where is all that imagery? going back to Doom titles i remember all of this was in the .WAD file, is there any way of hiding the bitmaps so that users can't just go editing them and ruining their app? apart from windows folder options i mean

Embedded resources or external data files. You can always put the files in an external database similar in concept to a WAD, and then use proprietary encryption to encode/decode them, but ultimately the end user can always edit the data files. All you can really do is make it more difficult for them to do so, but at the cost of making it more difficult for you to do so.

Thanks i will look into those options