SQL Server Reporting Services 2005 issue: Unable to load client print control

If you simply search on the error message within the subject then the best point of it is you get many references on how to resolve this issue.

Going back to root cause of the problem is that number of people have reported problems using the ActiveX print control in the report viewer after installing Microsoft Update 956391 having users receive the error "Unable to load client print control" when clicking on the print icon in the report viewer toolbar. 

The reason that Microsoft has deactivated on the list is a Kill-Bit (classified as an instruction to Internet Explorer to prevent it from loading an ActiveX control) which is called/used by an Active-X client print control used by the Reporting Services. I have found this explanation of KillBit-FAQ & details of that vulnerability are described in MS08-052 from the source.

Also the further explanation on the Report Viewer client viewer control from Brian Hartman's blog post that I would like to refer as follows:

....client print controls that shipped with SQL Server 2000, SQL Server 2005, Visual Studio 2008, and the Report Viewer 2008 redistributable all use the same CLSID and are therefore all disabled by the update. 

The previously shipped versions (using the first CLSID in the table) have been updated with a new version of GDI+ and a new CLSID to allow IE to load the control.  If you are using Report Server 2000, Report Server 2005, or the web control from VS 2008 in local mode, you will need to download an update so that your servers distribute the new print control.

Notice that SQL Server 2008 is not affected by this update and uses a different CLSID.  The print control that ships with SQL Server 2008 does not include the GDI+ DLL.  This DLL was included in earlier versions due to the requirement that they work on Windows 98 and Windows 2000. 

Brian also explains that it is supported to perform  directly in your application without a ReportViewer control with a new CLSID specification, and further explanation on how to resolve it:

To get to a working state, you will need to do the following:

1. Update your report server to distribute the updated client print control.
2. Update your ReportViewer redistributable so that it references the new CLSID.  The ReportViewer 2008 redistributable also includes an updated client print control for use in local mode.
3. Update Visual Studio.  This is for the same reason as the redistributable.  The ReportViewer is installed with Visual Studio for design time.
4. Update your Reporting Services SharePoint Add-In if you are using the report server in SharePoint integrated mode.

You need to the get the patch that is available from MS08-052 and particularly pay attention on the Microsoft SQL Server section. Depending on your software version or edition, you may need to choose between GDR and QFE software update links below in order to manually install your update from the Microsoft Download Center.