Mountain Lion slows down my iMac .
iMac 27 inch late 2009
3.06 GHz intel core 2 Duo
My computer was working really well despite its age until I installed the new Mountain Lion.
Now I find that it is much slower .
The main problem is between stiching from one programme or another I get the spinning wheel for maybe 10-15 seconds,
even switching between tabs in web browser .
Any genius to help with this problem ¿?¿?¿??¿
Thank you .