Could not load file or assembly CrystalDecisions.CrystalReports.Engine

If your ASP.NET application does reporting with the Crystal Reports version that comes with Visual Studio 2008 - Crystal Reports 2008 Basic - when you deploy that application to a fresh IIS installation, you will get the message "Could not load file or assembly 'CrystalDecisions.CrystalReports.Engine, Version=10.5.3700.0" etc etc etc. That's because the site needs the Crystal Reports runtime. There's a MSI installation package on machines with VS2008 installed, at C:\Program Files (x86)\Microsoft SDKs\Windows\v6.0A\Bootstrapper\Packages\CrystalReports10_5. Install the correct MSI (there's one for 32- and another for 64-bit machines), and the application should run ok.