- They notify, via the "\\Callback\\SetSystemTime" callback, components
of a change of system time (for example, Win32k).
Note, that our Win32k currently does not handle power callouts, so
it isn't affected by these changes (yet).
- NtSetSystemTime(NULL, ...) means "update system time using the current
time-zone information", which is something we don't implement yet.
(And, nothing was previously protecting this call from a NULL parameter...)