So I had this issue at work had to install on xp machine, dont ask why but just had to 🙂 and the error was NET 4, Visual Studio 2010 install fails on XP SP3 machine “Fatal error during installation”

Thus I was stuck installing Visual Studio 2010, I went and downloaded .net 4 standalone

And was having the same issues.

And went through the logs and found the error message was due a registry key (aren’t they always)

Product: Microsoft .NET Framework 4 Client Profile — Error 1402. Could not open key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Security\ServiceModel System error 5. Verify that you have sufficient access to that key, or contact your support personnel.

So I went to regedit, went to that key and added Administrators rights to it and run the installer again and everything was fine and installed vs2010 and .net 4 finally…………….

Anywayz just in case anyone runs into this issue again, this was the solution.