Hi all, I have an iMac, details as follows: iMac (27-inch, Late 2012) 3.2 GHz Intel Core i5 8 GB 1600 MHz DDR3 Startup Disk: Macintosh HD Graphics: NVIDIA GeForce GTX 675MX 1024 MB In the past two months, it has become very slow to respond to my input. For example, a search in Spotlight could take up to twenty seconds to produce the search results and clicking something on the horizontal Finder bar across the top of the display leads to the rotating beachball and, occasionally, a forced power down, using the power key and then restart. This occurs across many applications including Mail, Safari, iTunes and Pages, so I do not think this is an issue with a specific application. Any help would be much appreciated. Thank you!