Running SIW under WinRE
Windows RE is the Windows 7 (and Vista) replacement for the Windows XP Recovery Console.
It has two main purposes:
For example, you can start advanced tools such as Regedit to load registry hives and modify service status. By default, the registry editor loads the Windows RE environment's registry hive; you need to load the hives from the \%systemroot%\system32\config folder to make changes to the OS environment.
You usually access Windows RE from the Windows 7 (or Vista) installation media. After selecting your preferred language, click Next, then click "Repair your computer." A list of Windows 7 (or Vista) installations appears. You can add additional drivers to see other installations that are using non-bundled drivers. After selecting an OS, click Next.
The full list of options appears, including the ability to automatically repair an environment, revert to a previous system restore point, restore the computer from a backup, run the memory diagnostic tools, or open a command prompt for advanced system-recovery options.
More about WinRE @Microsoft.