How deep is the Win32 message queue?

Question

How many messages does the queue for a standard window hold? What happens when the queue overflows?

The documentation for GetMessage and relatives doesn

Answer 1

As stated in the MSDN article, if you need to worry about the size of the message queue, you might be better off redesigning your application.

Answer 2

10000 by default, but it can be adjusted via the registry.

If queue overflows, PostMessage fails.

Documentation here:

PostMessage function on MSDN