Visual Studio 2012 supports Windows 7 and newer. Windows Vista is unsupported, as is the server version of Windows Vista (Server 2008).
You will need to upgrade to at least Windows Server 2008r2 or Windows 7 (SP1) to install Visual Studio 2012.
You can build an application that targets Windows Vista or below, but you cannot run Visual Studio 2012 and newer on these operating systems.
Supported Operating System
- Windows 7 SP1 (x86 and x64)
- Windows 8 (x86 and x64)
- Windows Server 2008 R2 SP1 (x64)
- Windows Server 2012 (x64)
Source: http://www.microsoft.com/en-us/download/details.aspx?id=30678