vCenter 5.5 Failing to Install on Windows Server 2012 with Error 28173

Install the .NET Framework 3.5 package manually:

1. Go to the Control Panel
2. Click on Turn Windows Features On or Off
3. Click on the Next button
4. Click on the Next button
5. Click on the Next button
6. Click on the Next button
7. Select the .NET Framework 3.5 Features checkbox
8. Click on the Next button

Now you should be able to install VMware vCenter without this error.

If the above solution does not solve the problem, follow the instructions inside VMware KB 2048098 

Note: If you receive a message saying the Windows could not find the required files, you may need to insert the Windows setup media or have the server connected to the Internet. For futher information, refer to: https://support.microsoft.com/en-us/help/3002547/you-cannot-enable-the-microsoft--net-framework-3-5-feature-on-windows