I have an intel 2.0mhz 667 bus intel 17" late 2006 iMac. 3gb ram core 2 duo, 64bit Recently I bought on eBay a grey "iMac 10.4.11" disc-2007 Then 10.5.3 came out- I decided to buy a grey 10.5.2 disc-2008 "For Macintosh Computers" 2008-generic if ever, eh? well both are VERY machine specific! I was refunded, and told to keep the discs: there was no way to know ahead of time to if these would work or not, no matter how much research you did-unless you had one in front of you Digging down into the .mpkg OSInstall folder, then into DISTRIBUTION, a text editor opens a wonder world of info-geek talk: "If install encounters BAD MACHINES then FAIL install =true" [iMac 5,1;iMac 6,1;imac 7,1; iBook 3,1; etc]=Bad Machines [If we cant find it here, then we'll assume its OK to install] Then there is a "Look for 867 buss speed- if under that, FAIL install= true" Something of that nature... -- Now I KNOW there are ways around this, as others say they have done it; Even Mac OS X hints has a guide on how to. Now im no newbie, but i just havent been able to make a bootable install disc-the best ive done is an EFI boot disc- which doesnt boot. Anyone care to WALK me through it as if I knew nothing? I think some of the instructions ASSUME this and that-as techies often do-as they assume you know what they know-so you come up against dead ends I dont have any external storage save 3 1mb pocket drives, nor another intell mac Used to be you could at least put a grey imac disc on all imacs-et al In order to edit you must deconstruct the locked .dmg file, drag to a desktop folder, edit: erase the "Bad" list, ie:  and kick 667mhz up to 867; thats where I get lost-it seems that in order to be able to edit the locked .dmg, something breaks-restoring it back to a .dmg again gives me a useless EFI boot disc.........seems that Tiger and Leopard have slightly differing methods also. ...anyone?