Hi, I hope i post this in the right forum. Here is the full story, two weeks ago i was trying to change the hard drive on iMac 27" because the original one was failing. The Hard drive successfully changed but I broke the internal display connector bad luck I couldn't fix it myself so i sent it to a computer repair service called DT&T they fixed it by replacing the logic board but they didn't install the OS for me. When i got my iMac back i tried to put OS X.6 but i can't, i have the original discs that came with iMac and an extra Mac OS X retail DVD. The Hard drive I installed is a WD 2 TB, i formatted it to Mac OS extended journal and yes the partition is GUID 10 times. Still when i boot using the disc that came with the iMac it said "Mac OSX can't be Installed on this computer" So I tried the install DVD I had, when i put that in and restarted I hold "C" and the computer just stuck at Apple Logo grey screen and doesn't go anywhere. I left it for 2 hour still nothing happened. I went and red a lot of threads before writing this, and i have found no solution. I did try the target boot mode since there is no OS installed i can't repair the disc permission. So what is the problem? What i am doing wrong? I tried to use Remote install but i have lion in my Mac pro and it is not available in lion grrrr.. or i can't find it. Please help me, Thanks in advance for any replies, I am very frustrated and have 23 video projects that needs to be done. I do have a time machine back up of the computer. The computer had X.6 installed in it before i sent for repair.