First, have you installed Crystal Report correct version?
One thing, I had similar problem some time back and what I have found is, you need to specify exact version to be used.
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
</startup>
Source:
http://refat38.wordpress.com/2011/12/20/crvs2010-crdb_adoplus-dll-not-found/[
^]
Hope that helps