Errors installing ASP.NET 4.0

Here is a little problem you might run into when trying to use aspnet_regiis.exe to register ASP.NET 4 on a site.C:\Windows\Microsoft.NET\Framework\v4.0.30319>aspnet_regiis -i Start installing ASP.NET (4.0.30319). ....... Finished installing ASP.NET (4.0.30319). Setup has detected some errors during the operation. For details, please read the setup log file C:\Users\john\AppData\Local\Temp\