You can customize the behaviour and the appearance of Dicom Open Viewer simply editing dicom_window.ini file.
The file is subdivided in sections according to functionality. Each section is commented and is very simple modify them.

[Generale]Startup behaviour parameters.

AutoOpenImmaginiOnLoad: when the value is 1, the viewer shows automatically the images referenced by DICOMDIR file; when the value is 0 (default), the viewer show DICOMDIR tree.
AutoSelectOnLoad: when is set to 1, all the images are automatically selected on load; when the value is 0 (default), images are unselected.
AutoOpenDicomdir: when the value is 1, an existing DICOMDIR file in the folder with the application is automatically loaded on startup; if the value is 0 (default), no action is taken.
[Size Desktop]Startup size of the application window.

If Maximized is set to 1 (default), the window will fit the whole screen, if is set to 0 the window will be sized according to Height and Width parameters.
[Contenitori iniziali]Startup grid size

DirezioneX: viewport columns at startup (default 2);
DirezioneY: viewport rows at startup (default 2).
[Preset Window Center/Width]Windowing presets to be listed in Window/Level combo box.

To add a preset just add a row with description and values separated by "x" character (e.g. MyPreset=300x400).
[Mouse Sensibility]Set mouse sensibility (used in windowing).

Wheel: scroll sensibility (default: 12);
Move: move sensibility (default: 10);
Move16bit: move sensibility for 16-bit images (default: 1000).
[Combobox Window Center/Width]Adjustments to mouse sensibility used in windowing.

The corresponding values are multipliers for mouse sensibility values.
[Colors]Viewer color scheme.

Each color is in RGB format, with values separated by an hyphen (e.g. 0-89-179 means R=0, G=89, B=179). In presence of unrecognized values, default are used.
PanelBackground is the background color of the lateral panels and the startup panel (default: 27-27-53);
MenuBackground is the background for menu, tables and textarea (default: 169-207-255);
PatientDataLabel is the color of the labels superimposed to the images (default: 255-255-0);
RowHeaderBackground is the background color of the headers of the dump table (default: 165-165-165);
Label is the color of the labels (default: 255-255-255);
Panel is the background of the panel (default: 116-121-123);
Selection is the color of the selection border (default: 169-207-255);
bott is the color of buttons highlight (default: 116-121-123).
[Bitmap]Viewer icons and splash image.

Accepted format is Windows Bitmap (BMP)
If you want transparency you must use indexed BMP. Transparent color is the one of the bottom-left corner pixel.
Extension of the file must be specified (e.g. MyIcon=my_icon.bmp).
Default icon path is "Icons" folder located where dicom_widow.exe resides; is possible change the path by specifying the relative path to "Icons" folder (e.g. MyIcon="..\..\Alternate path\my_icon.bmp")
If the icon format is not correct or the icon file is not readable, it will be used the default icon.
[Hint]Application hints.

These hints appears when the mouse is over a button. Change this values in order to change viewer language.
[TabCaption]Captions of the application tabs.
[Label]Captions of the application labels.
[Default mouse]Default mouse behaviour labels.

Wheel: Wheel default behaviour is "Browse";
Right: Right button default behaviour is "Window/Level";
Left: Left button default behaviour is "Select Images";