Hello Barack ODrama.
I've had the same problem with mine once, if you have the lastest upgrade for it, it shoul'dnt be a problem, atleast that fixed my problem for the first time.
- I've had it to start up in 1 minute in some week's but then recently it started to get slowly again, and i have the lastest update's so if an update wont help, i guess i would have to look over this thread aswell, cause i have the same problem.
I also installed a Note(s) on mine, cause i'd had use to manage all my mails etc. do you have notes installed? .. if so, please tell.
but it's diffrently not a strange problem, cause i have some friends wich have it aswell
.
Other then you can use the HDD and reinstall the Macintosh OSX, as Tarek say's the one that came together with your comeputer, and yes remember to back everything up, so you won't loose it before you reinstall anything.
Good luck with fixing it, hope you get it sorted out.
Greetings Ashiz.