As we know in Windows 2012 server, the .NET Framework 3.5 (and older 3.0 and 2.0) is made available as an option.
We need to install .NET Framework 3.5 (and older 3.0 and 2.0) first if we want to install MS-SQL using SQL4SAP batch file on Windows server 2012.
There are four ways has been suggested on Microsoft .NET Framework 3.5 Deployment Considerations to fix this issue. However, no any solution worked for me at first glance.
After struggling for a quite good time and going through various docs, finally I found the solution which I thought to share here.
First run the system file checker tool in your windows 2012 server as there might be chances that few files are missing/corrupt.
To Run the system file checker tool
Start CMD as an Administrator
System file checker tool scan the system files and also repair missing or corrupted system files automatically.
It will take some time to complete the scanning and repairing. Once it is completed, use any of the methods discussed on Microsoft .NET Framework 3.5 Deployment Considerations to deploy .Net 3.5.1 framework on your windows 2012 server and proceed further with your database Installation.
Hope it will help to save your time.