Sql Reporting SP2: Unable to install RSClientPrint ActiveX control

Here is a response I wrote for a problem posted on the Microsoft Reporting Services newsgroup:

The original problem was with Sql Reporting Services SP-2 where an end-user was unable to install the new Client Side Printing ActiveX control:

Check the user's Security settings in Internet Explorer.  Depending on how it is setup, the browser may have disabled the ability to install ActiveX controls.

Typically, you can work around this by adding the URL of your Report website to the "Trusted Sites" zone.   To do this, go to Internet Explorer settings (Tools -> Internet Options), select the "Security" tab, click on the "Trusted Sites" icon, then click the "Sites" button to add your URL to this zone.   Once this is done, click okay to close the settings and try again.  You should see the small "Trusted" icon in the status-bar of your browser the next time you visit the Report website, and it should allow installing the ActiveX control.

If its still not working, you may have to adjust the security settings manually within Internet Explorer for this zone by clicking on the "Custom Level" button on that same Security tab.  There you can enable the "Download signed ActiveX controls", and "Run ActiveX controls and plugins" options.

This is a common problem with users running Windows XP SP-2 or within a company that pushes group security policies to users' PCs to lock-out certain features.  Another frequent cause is 3rd-party anti-virus and anti-spyware utilities that often block ActiveX controls entirely.