First we need to understand why IE9 will pop up the prompts. IE9 defaults to set an open timeout (0.2-second standard time) and IE9 prompts if the total load time used by all load controls exceeds this standard when we open the page. It is not possible to open the prompt manually, so you can wait for the prompt to appear and then modify it.
For the load time that the add-in requires, we can click "Manage Add-ins" in the Program tab of the Internet option and disable the add-in that takes a long time. In this, the time it uses to load the control is beyond our control.
We can also modify this standard time through the registry to reduce the add-on prompt notification, or simply let it stop appearing (make the standard Time big enough).
Please enter regedit in the Start Menu search box and click Enter to open Registry Editor. Navigate to the following key:
Hkey_current_usersoftwaremicrosoftinternet Explorermao Settings
In the right window, double-click the Addonloadtimethreshold value, change the DWORD value to decimal, and change the value to 200 (the default 0.2 second standard time).