IMac 27" won't boot into install disk - error

[mileslong]

Hi, i have read various threads about this but can't find a cure, here is what's happening:

1) Was running disk utility and said i have a corrupted disk
2) OSX runs fine but i can't reboot into startup disk in order to repair disk
3) Can only boot into OSX now by holding down Option key and selecting OSX
4) Can't use this method to boot into install disk or external drive.

Remedies, I have done the following:

1) Repaired permissions
2) SMC reset
3) PRAM reset
4) Wont allow me to safe boot
5) Won't allow me to boot from install disk
6) Won't install SL disk to try and repair install

I am really stumped here, any help??

Thanks,

Mark

 

[satcomer]

Unless you feel confident to do it yourself, you should take it to a technician to replace the malfunctioning drive. If you can boot to disk, something is really messing up.

 

[mileslong]

thanks for the response satcomer, dont know what to do