If you created reports using Visual Studio 2008 and Crystal Reports 2008 Basic (the one included with VS) and you want to deploy your app on a server, you'll also need to deploy the CR runtime. Your first reaction might be to go to the Business Objects Website and download the CR 2008 runtime.
Well, that's the wrong runtime. That one is for the "full" version of CR 2008 (version 12). The CR included with VS 2008 is the basic one (version 10.5).
So where do I get the basic (10.5) runtime? It's right on your machine:
C:\Program Files\Microsoft SDKs\Windows\v6.0A\Bootstrapper\Packages\CrystalReports10_5