The default dialog size of the samples supplied with the Microsoft Platform SDK are 370x270 installer units. Fortunately, Advanced Installer uses the same size. This equates to 370x270 pixels on a 72dpi screen, 493x360 on a 96dpi screen and 616x450 on a 120dpi screen. (Most people seem to use a 96dpi screen, although 120dpi is becoming more and more prevalent with laptops and LCD screens. I use both.)
The sample dialog and banner images supplied with Advanced Installer are apparently designed for a 96dpi screen. However, the images are the wrong size. The dialog images are 503x314. They should be 493x312. The banner images are 500x63. They should be 493x58. To prove this, I ran the following tests:
1. Create a dialog and banner image using the Advanced Installer sizes. Each image has a 1 pixel red border and a black and white dithered (checkerboard) fill pattern.
2. Create a test installer using the above images.
3. Build the installer using fixed-size images (Global Properties > Theme > Bitmap Display > Keep original picture size). Result: Dialog and banner images are both cropped (red border missing) on a 96dpi screen.
4. Rebuild the installer using stretched images (Global Properties > Theme > Bitmap Display > Stretch with fonts). Result: Red border is visible, but checkerboard pattern is squashed (black lines displayed).
5. Create a dialog and banner image using the correct sizes and repeat steps 3 and 4. Result: Both fixed-size and stretched images are perfect on a 96dpi screen.
Could you replace the sample images with the correct sizes in the next release?