imac not starting after erasing disc

[cypress822]

Erased my hard drive so i could sell it. When i turn it on, there is a question mark that blinks off and on. I had lion installed and therefore no disc. How do i reinstall a clean OS on to the hard drive? I do have an external bootable hard drive if that helps. I only have a wired keyboard...not a wired keyboard.

I was hoping when i restarted it, it would allow me to access the lion bootable recovery thing...but no luck

 

[Dadioh]

Erased my hard drive so i could sell it. When i turn it on, there is a question mark that blinks off and on. I had lion installed and therefore no disc. How do i reinstall a clean OS on to the hard drive? I do have an external bootable hard drive if that helps. I only have a wired keyboard...not a wired keyboard.

I was hoping when i restarted it, it would allow me to access the lion bootable recovery thing...but no luck

Have you tried holding down the "option" key while booting? That should give you access to the Lion recovery partition. If not, then you are going to need an installation DVD or USB stick.