How get an original OS load

[Dermako]

I have an iMac that I rarely use and want to give it to my folks.
I would like to reload the original OS to it (snow leopard) or even better yet go straight to Lion. I have made the bootable USB and loaded it on this machine and it just did the upgrade with all my old data on it.
How can I load Lion and have like new, or at least reload Snow Leopard as new and then upgrade to lion?
My folks are in there 70's and wear me out on Windows that I forget more about everyday, so a clean install and setup for them would be much easier than working around my old stuff.
Any help would be much appreciated.

 

[Dysfunction]

When you boot off of your bootable media, it will always upgrade.

That is, unless you CANCEL out of the install, select disk utility, then format the drive.

 

[bobtomay]

With Lion:

Reboot the machine holding the option key.

Select the Recovery partition - head into Disk Utility - Erase tab - erase and format

Back out of it and then do your clean install of Lion.

 

[Dermako]

Almost worked.
The bootable USB of Lion knows I bought it through Apple ID (tried to us my mothers ID).
Loaded Snow Leopard and will download Lion at there house.
Question though. If I purchase the USB from the Apple store, once it is loaded will it tag the USB to a particular Apple ID?

 

[harryb2448]

No it will work just like an install DVD and there is no activation tied to it like Windows.