Sometimes, the computer gets restarted automatically either after the full FC12 installation via Command Line Interface or after the installation of some of the external components. How to delay this behavior?
You need to use the /norestart parameter in your command line.
Also, if you know that it's due to a particular component, such as, for example, C++ Redistributable, you might want to try installing it via the command line in the silent mode upfront before calling the FC installer.
vc_redist.x86.exe /q /norestart