The native modules are not listed in the Modules Dialog box
Normally, after Agent installation, the 32 and 64-bit Web Server Agent modules of the respective AppMon major / minor version (for example, 7.2) should be registered and be selectable in the list of native modules. If those modules are deleted or unregistered, you can register them manually:
Open Internet Information Services (IIS) Manager by selecting Control Panels > Administrative Tools or by selecting Run from the Windows Start menu and entering
Select the IIS server (not a specific site) in the left pane and double-click Modules.
From the Actions menu top right, select Configure Native Modules.
Register the modules
<DT_HOME>/agent/lib64/dtagent.dll. Give them a descriptive name, like the default one: AppMon IIS Web Server Agent 7.2 [(x64)]. You can register both bitnesses of the same AppMon version with your IIS. You can also configure both bitnesses for the site you want to instrument and the bootstrap Agent chooses the right one. However, you should not have registered modules of the same bitness and different AppMon versions at the same time. The configured module is used, but all registered modules be load and initialize.
Clear any check boxes left of the newly registered modules, because this would enable these modules for all sites of the selected IIS. Normally you just want to configure the modules for selected sites of this IIS.
Click OK. You can now configure the modules for the sites.
Simultaneous IIS restart scenario
If you collectively restart your IIS instances, you should not have more than 50 Web Server Agents connected to one Collector, so the load does not overwhelm the Collector.