Dear Rick, on my new computer with Windows 7 all seems to work right, however every time I open a project in Visual Studio 2010 I get the message:
"ASP.NET 4.0 has not been registered on web server. You need to manually configure your web server for ASP.NET 4.0 in order for your site to run correctly".

I have the following 64 bit folder:
C:\Windows\Microsoft.NET\Framework64\v4.0.30319

I followed the fix suggested here, but also after reboot I get the message again:
https://www.aspsnippets.com/Articles/ASPNET-40-has-not-been-registered-on-the-Web-server-You-need-to-manually-configure-your-Web-server.aspx

Please, have you any solution?
Do I need to reinstall Asp.Net 4?
Thank you very much

I solved by installing SP1 for Visual Studio 2010 and the following update:
https://blogs.msdn.microsoft.com/webdev/2014/11/11/dialog-box-may-be-displayed-to-users-when-opening-projects-in-microsoft-visual-studio-after-installation-of-microsoft-net-framework-4-6/

I do not delete this post so it is useful for any other.