When you try to install Report Viewer 2008 on server 2012, it tells you that you need Microsoft .NET Framework 2.0, but you can’t install .NET 2.0 on Server 2012 from the link.
To fix this, go to add features and install .NET 3.5, which includes .NET 2.0. You should then be able to install Report Viewer 2008 on server 2012.
❗ To install .NET 3.5 on Server 2012, you will have to click on Specify an alternate source location before you click the Finish button on the feature install, then insert the Server 2012 installation media and specify the source to be D:\sources\sxs, where D is the drive containing the install media. The reason for this is because the binaries to install .NET 3.5 are not installed with Server 2012 for security reasons.