Troubleshooting the Boot Image
So, how can we troubleshoot drivers in the boot image? Well, quite easily; as soon as the setup starts (directly after you click Install now) you can press Shift+F10 to get a command prompt. In this command prompt you can, for example, type ipconfig to verify the network has been started, and you can use Diskpart to verify that you can access the disk.
Troubleshooting the Setup Engine
If the drivers are all there, but setup fails later-for example with the quite common error message, "Windows could not parse or process unattend answer file [C:\Windows\Panther\unattend.xml] for pass [Specialize]"-then the error itself doesn't give any meaningful information so we have to turn to the log files. When we look in the log file, we might see the real error, which is typically invalid product key for this error message.
The core Windows 7 setup log file is named setupact.log. There is also a setupact.err log that only contains error messages from the setup. The important thing to note about setupact.log file is that, depending on when setup fails, you will find the log file in different locations. For example, if setup fails very early in the process, before setup even have created the partition to deploy Windows 7 on, you will find the log file in the Windows PE RAM disk (called scratchspace), the path is X:\$WINDOWS.~BT\Sources\Panther. If setup fails a bit later, you will find the log file in C:\WINDOWS\PANTHER. For a complete listing of all locations, see KB 927521.