You might hit the error below when you are installing SQL Server 2012.
Error 1330.A file that is required cannot be installed because the cabinet file D:\1033_ENU_LP\redist\VisualStudioShell\VSIntSetup\cab12.cab has an invalid digital signature. This may indicate that the cabinet file is corrupt.
The file is most likely not corrupted but rather there is no way to install SQL 2012 in Windows Virtual Machine for Windows 7. I have been trying to install SQL 2012 since RC0 till RTM more than 6 times but it has never succeeded. It was fine when I install it into Oracle Virtual Box.