Elevating permissions is possible in Silverlight 5. You need to do the following:

1. Right-click the Silverlight project and check "Require elevated permissions when running in the browser" ;

2. When compiling a Silverlight program, a digital certificate must be used to sign Silverlight

xap;

3. The digital certificate for signing must be installed on the browser side ;

4. You must add a key value AllowElevatedTrustAppsInBrowser=1 in the client's registry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Silverlight;

5. Of course, you must install it on the browser Activex control to be loaded;

BTW, generally Activex controls can only run in IE-based browsers, not non-IE-based browsers such as Firefox.