The preferences dialog box can be opened from the Options menu, or by using the Ctrl+P shortcut. All the preferences configured in this dialog box are stored in ResEdit.xml. This file is loaded when you launch ResEdit, and saved when you quit. You can also modify ResEdit.xml by hand, it has a standard xml structure. If ResEdit doesn't find ResEdit.xml, it creates a new one with default parameters:

<!--ResEdit configuration file-->
    <includes />
    <unicode support="true" macro="" />
    <autoSaveLayout value="false" />
    <autoCheckUpdate value="false" />
    <maximized value="false" />
    <dialog autoResizeType="0">
        <grid width="5" height="5" visible="false" />
        <margin size="7" visible="false" />
        <snap sepSize="5" smallSepSize="2" visible="false" />
        <default type="Animation" width="20" height="20" name="" id="IDD_ANIMATION" />
        <default type="Button" width="50" height="14" name="Button" id="IDC_BUTTON" />
        <default type="CheckBox" width="48" height="30" name="Check" id="IDC_CHECKBOX" />
        <default type="ComboBox" width="48" height="30" name="" id="IDC_COMBO" />
        <default type="Custom Control" width="20" height="20" name="" id="IDC_CUSTOM" />
        <default type="Date Time Picker" width="100" height="15" name="" id="IDC_DATETIMEPICKER" />
        <default type="Edit Control" width="40" height="14" name="" id="IDC_EDIT" />
        <default type="Group Box" width="48" height="40" name="Static" id="IDC_STATIC" />
        <default type="Hot Key" width="80" height="14" name="" id="IDC_HOTKEY" />
        <default type="IP Address Control" width="100" height="15" name="" id="IDC_IPADDRESS" />
        <default type="ListBox" width="48" height="40" name="" id="IDC_LIST" />
        <default type="ListView Control" width="60" height="50" name="" id="IDC_LIST" />
        <default type="Month Calendar" width="140" height="100" name="" id="IDC_MONTHCALENDAR" />
        <default type="Picture Control" width="20" height="20" name="" id="IDC_STATIC" />
        <default type="Progress Bar" width="80" height="14" name="" id="IDC_PROGRESS" />
        <default type="Radio Button" width="20" height="20" name="Radio" id="IDC_RADIO" />
        <default type="Rebar Control" width="20" height="20" name="" id="IDC_REBAR" />
        <default type="Rich Edit 2" width="40" height="14" name="Rich Edit" id="IDC_RICHEDIT" />
        <default type="Scroll Bar" width="11" height="40" name="" id="IDC_SCROLLBAR" />
        <default type="Slider Control" width="100" height="15" name="" id="IDC_SLIDER" />
        <default type="Spin Control" width="11" height="14" name="" id="IDC_SPIN" />
        <default type="Static Text" width="20" height="20" name="Static" id="IDC_STATIC" />
        <default type="Tab Control" width="50" height="30" name="" id="IDC_TAB" />
        <default type="TreeView Control" width="60" height="50" name="" id="IDC_TREE" />
        <pixelGrid value="true" />
        <textureGrid value="true" color1="0x00CCCCCC" color2="0x00FFFFFF" />
        <background color="0x00F5DCD7" />
        <invertBackground color="0x008040FF" />

Layout preferences

Layout preferences (window size and position, panels size, ...) are stored in ResEdit.layout. Since this file contains binary data, it's not recommended to modify it by hand.