Setting computer to it's Original Settings

Do you just simply insert the reinstall disc and prompt it to do a erase and complete reinstall? I ask because I tried to do so months ago and was unsuccessful. I ended up spending hours on the phone with an apple rep who ended up saying... the discs were corrupt or there was an error with the actual discs and I needed new ones! I wonder if it was just operator error, which seems more likely
So I wondered if someone might be so kind as to let me know if there any key commands I should do or exactly how to reset it to it's original settings? THANKS!!!

Well, if you want to completely erase everything on your drive and reinstall a fresh copy of OS X, then you need to insert your installation disk and tell it to erase and install. Please note that this will COMPLETELY ERASE everything on your drive, so any files you want to keep you MUST backup before doing so. What exactly happened when you tried to do so before?