diff --git a/src/components/SettingsPanel.jsx b/src/components/SettingsPanel.jsx
index 26baf20..c044f6b 100644
--- a/src/components/SettingsPanel.jsx
+++ b/src/components/SettingsPanel.jsx
@@ -106,7 +106,8 @@ export const SettingsPanel = ({ isOpen, onClose, config, onSave }) => {
   const themeDescriptions = {
     dark: '→ Modern dark theme (default)',
     light: '→ Light theme for daytime use',
-    legacy: '→ Classic green terminal style'
+    legacy: '→ Green terminal CRT style',
+    classic: '→ 90s Windows retro style'
   };
 
   const layoutDescriptions = {
@@ -268,8 +269,8 @@ export const SettingsPanel = ({ isOpen, onClose, config, onSave }) => {
           <label style={{ display: 'block', marginBottom: '8px', color: 'var(--text-muted)', fontSize: '11px', textTransform: 'uppercase', letterSpacing: '1px' }}>
             Theme
           </label>
-          <div style={{ display: 'grid', gridTemplateColumns: 'repeat(3, 1fr)', gap: '8px' }}>
-            {['dark', 'light', 'legacy'].map((t) => (
+          <div style={{ display: 'grid', gridTemplateColumns: 'repeat(4, 1fr)', gap: '8px' }}>
+            {['dark', 'light', 'legacy', 'classic'].map((t) => (
               <button
                 key={t}
                 onClick={() => setTheme(t)}
@@ -279,12 +280,12 @@ export const SettingsPanel = ({ isOpen, onClose, config, onSave }) => {
                   border: `1px solid ${theme === t ? 'var(--accent-amber)' : 'var(--border-color)'}`,
                   borderRadius: '6px',
                   color: theme === t ? '#000' : 'var(--text-secondary)',
-                  fontSize: '13px',
+                  fontSize: '12px',
                   cursor: 'pointer',
                   fontWeight: theme === t ? '600' : '400'
                 }}
               >
-                {t === 'dark' ? '🌙' : t === 'light' ? '☀️' : '💻'} {t.charAt(0).toUpperCase() + t.slice(1)}
+                {t === 'dark' ? '🌙' : t === 'light' ? '☀️' : t === 'legacy' ? '💻' : '🪟'} {t.charAt(0).toUpperCase() + t.slice(1)}
               </button>
             ))}
           </div>
diff --git a/src/styles/main.css b/src/styles/main.css
index 235dbb7..0f29ce0 100644
--- a/src/styles/main.css
+++ b/src/styles/main.css
@@ -47,7 +47,7 @@
 }
 
 /* ============================================
-   THEME: LEGACY (Classic HamClock Style)
+   THEME: LEGACY (Green Terminal Style)
    ============================================ */
 [data-theme="legacy"] {
   --bg-primary: #000000;
@@ -70,6 +70,34 @@
   --scanline-opacity: 0.05;
 }
 
+/* ============================================
+   THEME: CLASSIC (90s Windows Style)
+   ============================================ */
+[data-theme="classic"] {
+  --bg-primary: #008080;
+  --bg-secondary: #c0c0c0;
+  --bg-tertiary: #dfdfdf;
+  --bg-panel: #c0c0c0;
+  --border-color: #808080;
+  --border-light: #ffffff;
+  --border-dark: #404040;
+  --text-primary: #000000;
+  --text-secondary: #000000;
+  --text-muted: #404040;
+  --accent-amber: #ffff00;
+  --accent-amber-dim: #c0c000;
+  --accent-green: #00ff00;
+  --accent-green-dim: #00c000;
+  --accent-red: #ff0000;
+  --accent-blue: #000080;
+  --accent-cyan: #008080;
+  --accent-purple: #800080;
+  --title-bar: linear-gradient(90deg, #000080, #1084d0);
+  --title-bar-text: #ffffff;
+  --map-ocean: #000080;
+  --scanline-opacity: 0;
+}
+
 * { margin: 0; padding: 0; box-sizing: border-box; }
 
 body {
@@ -87,6 +115,12 @@ body {
   font-family: 'JetBrains Mono', monospace !important;
 }
 
+/* Classic theme uses system fonts */
+[data-theme="classic"] body,
+[data-theme="classic"] * {
+  font-family: 'Tahoma', 'MS Sans Serif', 'Arial', sans-serif !important;
+}
+
 /* Subtle scanline effect */
 body::before {
   content: '';
@@ -97,6 +131,191 @@ body::before {
   z-index: 9999;
 }
 
+/* ============================================
+   CLASSIC THEME - 90s WINDOWS STYLING
+   ============================================ */
+
+/* 3D Beveled border effect for classic theme */
+[data-theme="classic"] .panel {
+  background: #c0c0c0 !important;
+  border: none !important;
+  border-radius: 0 !important;
+  box-shadow: 
+    inset -1px -1px 0 #404040,
+    inset 1px 1px 0 #ffffff,
+    inset -2px -2px 0 #808080,
+    inset 2px 2px 0 #dfdfdf !important;
+  backdrop-filter: none !important;
+}
+
+/* Classic window title bar style */
+[data-theme="classic"] .panel-header,
+[data-theme="classic"] .panel > div:first-child {
+  background: linear-gradient(90deg, #000080, #1084d0) !important;
+  color: #ffffff !important;
+  font-weight: bold !important;
+  padding: 2px 4px !important;
+  margin: -10px -10px 8px -10px !important;
+  font-size: 12px !important;
+}
+
+/* Classic buttons */
+[data-theme="classic"] button,
+[data-theme="classic"] .map-style-btn {
+  background: #c0c0c0 !important;
+  color: #000000 !important;
+  border: none !important;
+  border-radius: 0 !important;
+  box-shadow: 
+    inset -1px -1px 0 #404040,
+    inset 1px 1px 0 #ffffff,
+    inset -2px -2px 0 #808080,
+    inset 2px 2px 0 #dfdfdf !important;
+  font-family: 'Tahoma', 'MS Sans Serif', sans-serif !important;
+  font-size: 11px !important;
+  padding: 4px 12px !important;
+}
+
+[data-theme="classic"] button:hover,
+[data-theme="classic"] .map-style-btn:hover {
+  background: #dfdfdf !important;
+}
+
+[data-theme="classic"] button:active,
+[data-theme="classic"] .map-style-btn:active,
+[data-theme="classic"] .map-style-btn.active {
+  box-shadow: 
+    inset 1px 1px 0 #404040,
+    inset -1px -1px 0 #ffffff,
+    inset 2px 2px 0 #808080,
+    inset -2px -2px 0 #dfdfdf !important;
+}
+
+/* Classic inputs */
+[data-theme="classic"] input,
+[data-theme="classic"] select {
+  background: #ffffff !important;
+  color: #000000 !important;
+  border: none !important;
+  border-radius: 0 !important;
+  box-shadow: 
+    inset 1px 1px 0 #404040,
+    inset -1px -1px 0 #ffffff,
+    inset 2px 2px 0 #808080,
+    inset -2px -2px 0 #dfdfdf !important;
+  font-family: 'Tahoma', 'MS Sans Serif', sans-serif !important;
+  font-size: 11px !important;
+  padding: 2px 4px !important;
+}
+
+/* Classic scrollbars */
+[data-theme="classic"] ::-webkit-scrollbar {
+  width: 16px;
+  height: 16px;
+}
+
+[data-theme="classic"] ::-webkit-scrollbar-track {
+  background: #c0c0c0;
+  background-image: 
+    linear-gradient(45deg, #808080 25%, transparent 25%),
+    linear-gradient(-45deg, #808080 25%, transparent 25%),
+    linear-gradient(45deg, transparent 75%, #808080 75%),
+    linear-gradient(-45deg, transparent 75%, #808080 75%);
+  background-size: 4px 4px;
+  background-position: 0 0, 0 2px, 2px -2px, -2px 0px;
+}
+
+[data-theme="classic"] ::-webkit-scrollbar-thumb {
+  background: #c0c0c0;
+  border-radius: 0;
+  box-shadow: 
+    inset -1px -1px 0 #404040,
+    inset 1px 1px 0 #ffffff,
+    inset -2px -2px 0 #808080,
+    inset 2px 2px 0 #dfdfdf;
+}
+
+[data-theme="classic"] ::-webkit-scrollbar-button {
+  background: #c0c0c0;
+  box-shadow: 
+    inset -1px -1px 0 #404040,
+    inset 1px 1px 0 #ffffff;
+  width: 16px;
+  height: 16px;
+}
+
+/* Classic links */
+[data-theme="classic"] a {
+  color: #0000ff !important;
+  text-decoration: underline !important;
+}
+
+[data-theme="classic"] a:visited {
+  color: #800080 !important;
+}
+
+/* Classic header styling */
+[data-theme="classic"] [style*="gridColumn: '1 / -1'"] {
+  background: #c0c0c0 !important;
+}
+
+/* Classic text colors override */
+[data-theme="classic"] [style*="color: var(--accent-cyan)"],
+[data-theme="classic"] [style*="color: var(--accent-amber)"],
+[data-theme="classic"] [style*="color: var(--accent-green)"] {
+  color: #000080 !important;
+}
+
+/* Classic modal/dialog styling */
+[data-theme="classic"] [style*="position: fixed"][style*="background: rgba"] {
+  background: rgba(0, 128, 128, 0.9) !important;
+}
+
+/* Classic table styling for DX cluster */
+[data-theme="classic"] table,
+[data-theme="classic"] [style*="display: grid"] {
+  border-collapse: collapse;
+}
+
+[data-theme="classic"] tr:nth-child(even) {
+  background: #dfdfdf;
+}
+
+[data-theme="classic"] tr:nth-child(odd) {
+  background: #c0c0c0;
+}
+
+/* Classic Leaflet overrides */
+[data-theme="classic"] .leaflet-container {
+  background: #000080 !important;
+}
+
+[data-theme="classic"] .leaflet-control-zoom {
+  border-radius: 0 !important;
+}
+
+[data-theme="classic"] .leaflet-control-zoom a {
+  background: #c0c0c0 !important;
+  color: #000000 !important;
+  border-radius: 0 !important;
+  box-shadow: 
+    inset -1px -1px 0 #404040,
+    inset 1px 1px 0 #ffffff !important;
+}
+
+[data-theme="classic"] .leaflet-popup-content-wrapper {
+  background: #c0c0c0 !important;
+  border-radius: 0 !important;
+  box-shadow: 
+    inset -1px -1px 0 #404040,
+    inset 1px 1px 0 #ffffff,
+    2px 2px 4px rgba(0,0,0,0.5) !important;
+}
+
+[data-theme="classic"] .leaflet-popup-tip {
+  background: #c0c0c0 !important;
+}
+
 /* ============================================
    ANIMATIONS
    ============================================ */
@@ -120,6 +339,13 @@ body::before {
   border-top-color: var(--accent-amber);
 }
 
+/* Classic theme uses hourglass cursor for loading */
+[data-theme="classic"] .loading-spinner {
+  border-radius: 0;
+  border-color: #000000;
+  border-top-color: #808080;
+}
+
 /* ============================================
    LEAFLET MAP CUSTOMIZATIONS
    ============================================ */
@@ -198,6 +424,13 @@ body::before {
   border: 2px solid #aaaacc;
 }
 
+/* Classic theme markers - square */
+[data-theme="classic"] .custom-marker,
+[data-theme="classic"] .de-marker,
+[data-theme="classic"] .dx-marker {
+  border-radius: 0 !important;
+}
+
 /* ============================================
    MAP STYLE SELECTOR
    ============================================ */
@@ -308,6 +541,15 @@ body::before {
   border-top-color: #ffffff !important;
 }
 
+/* Classic tooltips */
+[data-theme="classic"] .dx-tooltip {
+  background: #ffffcc !important;
+  border: 1px solid #000000 !important;
+  border-radius: 0 !important;
+  color: #000000 !important;
+  box-shadow: 2px 2px 0 #000000 !important;
+}
+
 /* ============================================
    SCROLLBAR STYLING
    ============================================ */
diff --git a/src/utils/config.js b/src/utils/config.js
index 8afc553..0659e9a 100644
--- a/src/utils/config.js
+++ b/src/utils/config.js
@@ -7,7 +7,7 @@ export const DEFAULT_CONFIG = {
   callsign: 'N0CALL',
   location: { lat: 40.0150, lon: -105.2705 }, // Boulder, CO (default)
   defaultDX: { lat: 35.6762, lon: 139.6503 }, // Tokyo
-  theme: 'dark', // 'dark', 'light', or 'legacy'
+  theme: 'dark', // 'dark', 'light', 'legacy', or 'classic'
   layout: 'modern', // 'modern' or 'legacy'
   refreshIntervals: {
     spaceWeather: 300000,