System restore

[t-4-2]

I have a question.
If I were to do a system restore choosing a date, say 16th when a Windows
update was installed, why did I have to re-install that update afterwards ??
I always thought if I did system restore choosing 15th, THEN I would have to
re-install that update.
Furthermore, if that update was one of those " cannot be uninstalled ", why
did it reappear after the system restore ?
Thank you.
t-4-2

 

[DL]

If the update automatically created a sys restore then that restore is prior
to the update