I had a drive crash and when it was replaced the tech installed Tiger even though I paid for Leopard and got the dvd's. The reason he used Tiger was because there was no dvd drive on the computer. How can i go about installing the Leopard for which I paid? I tried to use my iMac dvd player as a connected unit but the install shuts off the computer and you have to start over again in an endless loop. Any tips?