This is the 24' model that takes the 2006 5.1 imac and tiger. I bought leopard but it wont install it straight up, so I got the tiger I hit the C and it will not load. I hit the D upon start up and it says "OUCH!!.mshdlr loc zero not zero...ooooo7oo7oooooe@eeeeeeeeeeeeeeeeeeh" repeating. makes me feel uneasy. Oh I bought the mac at auction it says its a imac6.1 is there a trick to load OS on mack's ??? Thanks.