Trying to upgrade to tiger

The imac doesn't want to boot from the DVD. so i try target disk mode, install from my leopard imac. of course that won't work. what should i do here?

edited to add... i don't care what's on this 10.2 disk. i can erase it if necessary, but it still won't boot from the dvd.

Perhaps your iMac only reads CDs if it is too old. What version of iMac is this one?

Or the DVD is a silver grey coloured system restore disc which will work ONLY on the model it came with? You may need to go out, spend a buck on the black coloured full retail install version of Tiger.

And do as Chilbear suggests, check the Imac does have a DVD reader as Tiger on CD's is harder to find that hens teeth!

dvd drive....

this is my step mom's old mac, and she doesn't remember the password, so it's preventing the upgrade if i try from within 10.2.