Unloading DLL from all processes after unhooking global CBT hook

Question

How do you properly unload a DLL from all processes when the system-wide hook that loaded them gets unloaded?

From MSDN:

You can release a gl

Answer 1

Hook dll are unloaded in their message loop. Forcing them to pass in the message loop help to unload them.

Add this after your UnhookWindowsHookEx to force all message loops to wake up :

DWORD dwResult;
SendMessageTimeout(HWND_BROADCAST, WM_NULL, 0, 0, SMTO_ABORTIFHUNG|SMTO_NOTIMEOUTIFNOTHUNG, 1000, &dwResult);

However I still have the issue from time to time. I don't know where it's coming from. I suppose a locked process could prevent the dll to unload, but I have no proof of that.