Hi I inherited a late 2006 white imac intel core duo, after installing the os the machine worked fine then after began to move sluggish, so I decided to install a new HDD and then the problems began. Everytime I do the installation there is an error so I thought I got a bad HDD so I tried another same issues won't install. So I decided to install the OS on an external drive to test if there is an issue with the disc, it installed without a problem. so I figured it had to be the HDD, so I placed back the original hdd in it booted fine then I attached one of the new hdd to an external enclosure and tried the installation, and guess what it worked! my issue is that I would like the hdd inside the machine, so I was wondering could there be something wrong with the sata cable or the sata connector on the board?