My iMac (27", Mid 2011 model) is unable to download any software update properly.
For example, let's say I select an update from software update. It will proceed to download. But once it comes to starting the downloaded installation program, software update will report that the file is corrupted, and then abort.
Also tried numerous time, I am still unable to download the 'Install Mountain Lion' from App Store.
Ran disk utility already. The 'verify' function has identified some issue and supposed correct it.
Harddisk capacity is 1Tb, and only around 85% used.