Handle Limitations

Some objects, such as user and GDI objects, support only one handle at a time. The system provides the handle when an application creates the object and invalidates the handle when the application destroys the object. Other objects, such as some kernel objects, support multiple handles to a single object. The operating system automatically removes the object from memory after the last handle to the object is closed.

The total number of open handles in the operating system is limited only by the amount of memory available to the operating system. However, a single process may have no more than 16,384 open GDI object handles. The per-process limit on kernel handles is 2^30. There is no per-process limit on user handles, but there is a systemwide limit of 65,536.