SHUTDOWN AND POWERON TAKES 3 MIN +

after i updated my macbook to 10.10.3 it has been slow down and takes about 3 minutes or plus to shut down and start up i need an help and a professional help with guided instruction as i m new user of mac but have used iphone from 3 years NOT THAT DUMB

NOTE : i uninstalled parellel desktop and windows from my mac after the update