If you are using Visual Studio 2010 and a Windows Forms Application which uses the Report Viewer control, then might have probably been scratching your head when you suddenly lost the capability of using any of the drill-through options in your reports.

The problem happens only after you install Visual Studio Service Pack 1! So, what is the solution… Install an update released for Visual Studio 2010 Service Pack 1 (KB2549864).

If you are using only the Microsoft Report Viewer 2010 SP1 Redistributable Package, then you need to install the file named “ReportViewer.exe”. If you use Microsoft Visual Studio 2010 Service Pack 1, install the file that is named “VS10SP1-KB2549864-x86.exe.” I saw yet another question on this being raised on this again this week… So I thought that a quick blog post on this would be definitely worth the effort!

Reference: Update fixes several Report Viewer issues after you install Visual Studio 2010 Service Pack 1 http://support.microsoft.com/kb/2549864

Brian Hartman’s Blog
http://blogs.msdn.com/b/brianhartman/archive/2011/03/31/visual-studio-2010-sp1.aspx

Addition: 10/22/2014: A number of people have reported that the above link does not work anymore for downloading the hotfix files. You will need to download the hotfix files from the link mentioned below:

Update for Microsoft Visual Studio 2010 Service Pack 1 Report Viewer (KB2549864)
http://www.microsoft.com/en-us/download/details.aspx?id=27231