Today I came across an error when trying to install SQL Server 2012 on Windows Server 2012 R2. There are several options to fix this error. Using Server Manager, Command Prompt or using PowerShell. Make sure you mount the OS cd before going forward. (D: is my CD Drive)
TITLE: Microsoft SQL Server 2012 Setup
The following error has occurred:
Error while enabling Windows feature : NetFx3, Error Code : -2146498298 , Please try enabling Windows feature : NetFx3 from Windows management tools and then run setup again. For more information on how to enable Windows features , see http://go.microsoft.com/fwlink/?linkid=227143
Fix Using Server Manager
Open Server Manager under manage select “Add Roles and Features”. Then select .NET Framework 3.5 Features click Next
As the binaries for .NET Framework 3.5 Features not copied with the OS make sure you insert the Server OS media. You can find it in the warning as well. Click on “Specify and alternate source path” to explicitly specify the source location. In my case its D:\sources\sxs. Then resume the setup.(Just Next Finish)
Fix Using Command Prompt or PowerShell
In Command prompt as administrator and run dism /online /enable-feature /featurename:NetFx3 /source:d:\sources\sxs
If you are using powerShell run Add-WindowsFeature NET-Framework-Core -Source D:\sources\sxs in elevated mode.
After installing .NET 3.5 I was able to install SQL 2012 successfully.
For further details you can refer Microsoft’s support article http://support.microsoft.com/kb/2734782