What should you do?

You have a computer that runs Windows Vista (x86). You need to perform a clean installation of Windows 7 (64-bit). What should you do?

A.
From the Windows 7 installation media, run Rollback.exe.

B.
From the Windows 7 installation media, run Migsetup.exe.

C.
Start the computer from the Windows 7 installation media. From the Install Windows dialog box, select the Upgrade option.

D.
Start the computer from the Windows 7 installation media. From the Install Windows dialog box, select the Custom (advanced) option.

Explanation:
When you are performing a clean installation, you should select Custom (Advanced). Almost all installations of Windows 7 that you will perform will be of the Custom (Advanced) type rather than upgrades. You can initiate upgrade installations only from within Windows Vista or Windows 7.
NOT Rollback, Migsetup, or Upgrade:
Specified clean installation not migration, update or rollback.