I currently have an early 2008 iMac (intel 2.66 ghz, 4 gig ram). I was planning on upgrading my HD with an SSD to speed up the performance of the computer. While I was backing up my old hard drive, the screen started to show floating dots, and artifacts all over the screen. I thought the HD was failing, and went forward with the new drive. Once the new drive was installed, I had the same issue, and in addition, I could not install the OS. I put the old HD back, and currently am restoring the OS, as per the discussion i had with the Apple tech. During the re-install, I am still having lines and dots (picture below). I am thinking it is the display or the video card. Would anyone have any thoughts? Given the age of the computer, I wouldn't fix it, unless it is something I can do myself cheaply. Thank you for any help you provide.