This is the message I got, while running SharePoint prerequisites.

Microsoft .Net Framework 4.5 equivalent products already installed (no action taken).

However, the setup was constantly throwing the following error:

Setup is unable to proceed due to the following error(s):
This product requires Microsoft .Net Framework 4.5.

Reason

The reason for this issue was that I had .Net Framework 4.6.2 installed on my machine which, was not recognized by the SharePoint setup.

Solution

1) Extract the installation media to a writable location

• If the installation media is an executable file (.exe) then, extract the files and folders to writable location by running the following command at command prompt.
  

  [executable file name] /extract:[path to a writable locatio]>

  For example,

  sharepoint.exe /extract:C:\SharePointInstaller

• If your installation media is an ISO or IMG disc image (.iso or .img), mount the disc image, and then copy the files and folders from the disc image to a writable location.

2) Download the zip file that contains the fix for your product

• SharePoint Foundation 2013 with Service Pack 1 fix
• SharePoint Server 2013 with Service Pack 1 fix
• Project Server 2013 with Service Pack 1 fix

3) Extract the zip file.

4) As per your case scenario, copy any of the following appropriate file from the zip folder, and paste it into the updates folder of your writable location.

• SharePoint Foundation 2013 with Service Pack 1:: wsssetup.dll
• SharePoint Server 2013 with Service Pack 1:: svrsetup.dll
• Project Server 2013 with Service Pack 1:: svrsetup.dll

5) Finally, run the setup again. Setup will now use the fix (support files) from the updates folder.

You can always refer to this support link for any further assistance.