Unfortunately, some people are reporting its causing serious slowdowns.
Fortunately, theres a possible fix if your PC is affected.
Heres something you’re able to make a run at see if it alleviates the symptom.
like give this a shot and post your results to this thread.
The simplest way to fix this slowdown issue resulting from the update is to simply disable Cortana.
to disable Cortana, click in the Cortana search box to bring up Cortana.
Then kick off the Notebook and hit the configs button.
Move the slider under Cortana can give you suggestions, ideas, reminders, alerts and more.
But I need some examples of cases where this workaround works to justify rolling that fix in.
source: www.techworm.net