Stream Writer cant find part of path

Hello, the problem i am having is when i try to use my Stream Writer to make my XML file it says it cant find part of the path, heres the code.

 XmlSerializer serial = new XmlSerializer(typeof(Combo));
 FileStream fileStream = new FileStream(@"Combos\"+combo.Name+".xml", FileMode.Create);
 serial.Serialize(fileStream, combo);

Heres the error

 DirectoryNotFoundException: Could not find a part of the path"C:\Users\Admin\Desktop\Battle Brawl\Combos\Name.xml".
 System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean anonymous, FileOptions options)
 System.IO.FileStream..ctor (System.String path, FileMode mode)
 (wrapper remoting-invoke-with-check) System.IO.FileStream:.ctor (string,System.IO.FileMode)
 ComboCreator.OnGUI () (at Assets/Editor/ComboCreator.cs:108)
 System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)