fixed root button

src/main/java/cz/kamma/kfmanager/ui/FilePanel.java

@@ -189,8 +189,7 @@ public class FilePanel extends JPanel {
     rootButton.setToolTipText("Computer / Root");
     rootButton.addActionListener(e -> {
         if (MainApp.CURRENT_OS == MainApp.OS.WINDOWS) {
-            // On Windows, the "root" is typically C:\
+            loadDirectory(resolveWindowsCurrentDriveRoot());
-            loadDirectory(new File("C:\\"));
         } else {
             loadDirectory(new File("/"));
         }
@@ -767,6 +766,34 @@ public class FilePanel extends JPanel {
         return "%.1f".formatted(gb);
     }
 
+    private File resolveWindowsCurrentDriveRoot() {
+        // Prefer root of the active tab's current directory, e.g. D:\\ when browsing D:.
+        File currentDir = getCurrentDirectory();
+        if (currentDir != null) {
+            try {
+                java.nio.file.Path rootPath = currentDir.toPath().toAbsolutePath().normalize().getRoot();
+                if (rootPath != null) {
+                    return rootPath.toFile();
+                }
+            } catch (Exception ignore) {
+            }
+        }
+
+        // Fallback to selected drive in dropdown.
+        Object selected = driveCombo != null ? driveCombo.getSelectedItem() : null;
+        if (selected instanceof File drive) {
+            return drive;
+        }
+
+        // Final fallback: first available filesystem root.
+        File[] roots = File.listRoots();
+        if (roots != null && roots.length > 0) {
+            return roots[0];
+        }
+
+        return new File("C:\\");
+    }
+    
     /**
      * Request focus on the table in the current tab
      */