Starting/using SQL Server Management Studio from Visual Studio

I have Visual Studio 2012 installed on a Win7 x64 machine. I know it has a SQL Server Management Express version installed on it. I am unsuccessfully trying to install SQL Server Management Studio 2012 Developer Edition since 2 weeks (tried like 20 times, with all the option, full install, upgrade, did all the tests, tried the setup checks and all the test were passed, did the whole process on many different virtual machines to start again with a clean OS, anything...) but the setup always fails. Stupid Microsoft can't even make his own software work together. Whatever. I see some people using SQL Server on his own.

Error is:

'Microsoft.VC80.ATL,version="8.0.50727.6229",publicKeyToken="1fc8b3b9a1e18e3b",processorArchitecture="x86",type="win32"'. Per ulteriori informazioni, consultare Guida e supporto tecnico. HRESULT: 0x800706BE.

I never really got what's the difference from using it within Visual Studio or on its own, but I need the program on its own because I have a book which teaches you to use SQL Server Management Studio on his own, not on Visual Studio. I need it because I don't even have an idea on how to manage a db alone, imagine doing it through Visual Studio...

So that ebook will teach me.

I googled for the aforementioned error but I didn't managed to solve the error.

I really need some help, this bad software is making me mad.

Thanks anyone, and sorry if I've been rude or something, I'm driven by frustration.

Note for mods:

Usually you like to close my questions with motivations like "It's not a question", "Not related to programming". Fail. It is, plus there are plenty of questions like these which don't get closed and are useful for everyone. You won't win prizes for closing/editing as many questions as possible, plus you're not making the community a favor. I know this question will get bashed over and over by some purists which have nothing better to do and from mods, but face the truth, and possibly deal with it.

Many thanks everyone.