You have uninstalled Vault 2010 or Vault 2011.
Now you try to install Vault 2012 and you get an error:
"Error 1603 - Visual Studio c++ Redist. 2010"
Solution:
1. Please backup your registry
2. try to delete following registry key (please backup your registry before):
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\VisualStudio\10.0\VC\VCRedist\x86
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\10.0\VC\VCRedist\x86\Bld
3. Retry the installation