Nope to your question about lagginess of a PC.
However, when you restart the PC without shutting down, it's called
a warm boot, and it will be faster.
If you shut down the PC, turns off the power, turns it back on,
it's called a cold boot, and things will be slightly slower.
You can, however, restart a PC automatically. I have files for
that, using the restart program in Windows. I won't recommend that,
lest you click on it accidentally and say bye bye to your unsaved
work. 
