MDT 2010 allows you to press F8 during the install process in order to open a WinPE command prompt if this is needed. You might want to disable this functionality however in a production deployment environment to prevent end-users from accidentally interrupting installation.
To disable F8 keypress functionality for MDT, use Notepad to open the the winpeshl.ini file found in the C:\Program Files\Microsoft Deployment Toolkit\Templates directory of your MDT 2010 installation and replace /Bootstrap with /BootstrapNoSF8 in these text files.
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