Follow these in the same order.
The first thing that you should verify is the version that you have installed. Please check if it matches with the version you have used in the ASP.Net application.
Ensure that the same version is being referenced in your configuration file. In this case - the web.config file should have entires pointing to the same version that you are installing and using.
This error on your screenshot may also be due to installation of the full version of Crystal reports. You would have to install only the runtime in this case. I see you mention 2008 - so I assume that you used the one is with visual studio 2008, then it is v10.5. You can find the msi for installation of v10.5 on your machine itself. Uninstall the current version from the server, and install from the msi found in the location below.
X:\Program Files\Microsoft SDKs\Windows\v6.0A\Bootstrapper\Packages\CrystalReports10_5
[Change X to the installation drive on your machine.]
If the above one does not solve, then ensure that your project is built with the right platform. Crystal reports 2008 is 32 bit only program. Go to the project , right-click and choose "Properties". In the Build tab - set the "Platform Target" to x86, and build your project. Re-deploy the application.
One of them would have solved your problem.