An imac running Yosemite will be sold and want to wipe out everything personal, but without formatting the system drive or reinstalling the OS. As far as personal stuff, the following have been done on the iMac. 1. There are a few applications installed 2. An email account has been set in Mail 3. A lot of browsing with Safari 4. As for file use, there was an external USB3 hard drive connected, nothing written on the system drive, other than the apps installed! Apart from the listed "personal" stuff above, are there others that must be wiped out that i have not thought of?