I just had that occur to me - no jpg dialog box, even though "show" was checked. I'm on Windows 7 and Irfanview 4.53. (Will now upgrade to 4.54, 32 bit. Solved after looking here by closing Irfanview, then re-trying but with PNG instead of jpg. Got the dialog box. Tried then as jpg, and it was there as it should be! No idea why it temporarily did not appear! Thanks!