System won't allow me to install a backward version.
Below are details from the error log.
It's looking for an entry for KB2390372 in the registry.
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=== Log extract ===
KB2390372v2 does not apply, or is blocked by another condition on your computer.
2015-04-07 09:51:38Z Performing a .NET version check for prerequisite 'Hotfix for Microsoft .NET Framework 4.0 (KB2390372)'.
2015-04-07 09:51:38Z Searching for a minimum version of '4.0.30319.0'.
2015-04-07 09:51:38Z Version found: '4.0.30319.0'.
2015-04-07 09:51:38Z Searching for a minimum version of '4.0.30319.0'.
2015-04-07 09:51:38Z Version found: '4.0.30319.0'.
2015-04-07 09:51:38Z Performing a registry key existence check for prerequisite 'Hotfix for Microsoft .NET Framework 4.0 (KB2390372)'.
2015-04-07 09:51:38Z Checking for the existence of the registry key 'HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\Updates\Microsoft .NET Framework 4 Client Profile\KB2390372'.
2015-04-07 09:51:38Z The registry key 'HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\Updates\Microsoft .NET Framework 4 Client Profile\KB2390372' was not found.
2015-04-07 09:51:38Z Check failed.
2015-04-07 09:51:38Z Check failed.
2015-04-07 09:51:38Z Resolution: Download and install the hotfix from go.microsoft.com/fwlink