Some applications automatically (or when asked) set themselves as a 'startup item', which causes them to open at every restart or login. They should be manually removed so that my iMac runs in a smooth condition, or simplify the jobs with the iMac cleaner.
There are still a few hidden data and applications inside my iMac that is still hogging the disk space. The initial reaction if the iMac is slow is that I delete a couple of applications and software to widen its memory space however, that would never solve the problem. Getting frustrated with my slow iMac will get me nowhere.
