cxlibw-5-0.dll was not found

However every once in a while we are getting the following error message: 

"This application has failed to start because cxlibw-5-0.dll was not found.  Re-installing the application may fix this problem."

das programm kann nicht gestartet werden, da cxlibw-5-0.dll auf dem computer fehlt. Installieren Sie das Programm erneut, um das Problem zu beheben

EDIT:- with thanks to Theo I made a few amendments to his solution to get it working for C# and it seems to work nicely...
 
public void SetCrystalReportsPath()
{
               string crystalReportsPath = Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles) + "\SAP BusinessObjects\Crystal Reports for .NET Framework 4.0\Common\SAP BusinessObjects Enterprise XI 4.0\";
 
               if (Environment.Is64BitProcess)
               {
                    crystalReportsPath += "win64_x64";
               }
               else
               {
                    crystalReportsPath += "win32_x86";
               }
 
               Environment.SetEnvironmentVariable("path", Environment.GetEnvironmentVariable("path") + ";" + crystalReportsPath);
               IntPtr intPtrZero = IntPtr.Zero;
               SendMessageTimeout((IntPtr)0xffff, 0x001A, intPtrZero, "Environment", 2, 5000, intPtrZero);
}

http://scn.sap.com/thread/3203841