Assuming that you're trying to install Virtual Families 1.00.09 in Windows Vista or later, it's likely that you are receiving that error because the User Account Control component of Windows is blocking access to the specific registry keys required by the game's setup program. Since updating the game changes the Windows registry, you must ensure that both the user account and the setup program have the necessary permissions in order to make registry changes.

You can turn off User Account Control temporarily while installing the update (refer to Windows Help to learn how to do that). You can also refer to support documentation on Microsoft's support site to see how to set up permissions on your computer to resolve that error.