回答“MacBook Pro Mid 2012 is very slow to respond to anything”So many times, People are complaining about a slow performance issue due to several reasons. (1) The startup is loaded with lots of programs. (2) Presence of the virus. (3) Files are not organized or update required. These are some basic reasons for slow performance. you should keep the minimum programs on the startup files. Now run a good antivirus on your mac pc. it will clean up the mac and make your computer secure. if briefing, you may visit: why is my MacBook Pro running slow?