We faced two scenarios using Windows 2012 64 bit Server and Crystal Reports 10.2.0.
In the first one, everything is working fine until now.
In a second one, I was working fine too, except when someone would try to save the report as an Excel file. It would crash the IIS ASP.Net process. Something on KERNEL32.dll, but I don't have the full message in English to post.
We tried to format the server and reinstall Windows 2012 Server, but it was useless.
We researched about it and all the references and possible solutions ended up at an orientation to install Crystal Reports 13.0.12.
We installed the newer version and everything is working fine.
Please note the the version numbers are a bit confusing. I always check the version number in windows "programs and resources".