.NET Framework v4 refuses to install (Visual Studio 2010)

[Samuka97]

So I have been trying for the past 4 days to upgrade to Visual Studio 2010, but I can't install the demo. It doesn't install .NET Framework 4, so it doesn't even attempt the rest. I tried installing it by downloading a stand-alone from the internet and it says "Installation failed: Access Denied".

Yes, I ran it as an administrator. After that, it opens up a window with this on it (sorry for the portuguese):
[quote] Nome do Evento de Problema: VSSetup
Assinatura do Problema 01: Microsoft .NET Framework 4 Setup
Assinatura do Problema 02: 4.0.30319
Assinatura do Problema 03: 10.0.30319.1
Assinatura do Problema 04: 1
Assinatura do Problema 05: Windows6.1-KB958488-v6001-x86.msu
Assinatura do Problema 06: Install_I_Interactive_Error
Assinatura do Problema 07: 0x5
Assinatura do Problema 08: 5
Assinatura do Problema 09: unknown
Versão do sistema operacional: 6.1.7600.2.0.0.256.1
Identificação da Localidade: 1046[/quote]

So Facepunch, what's the deal with this?!