Best way to wipe out main HD?

[Colorblind]

I'm new to Macintosh, can someone tell me the best way to erase my entire hard drive, without deleting the OS X? I don't really want to do this, but it seems that's my only option. I've been getting an "Assertion error" every time I try to launch Pro Tools, and it seems no one can help me. I've uninstalled/reinstalled, and still the same error continues to pop up. Digidesign won't even reply to my emails. Someone please explain to me the best course of action.
Thanks,

Colorblind

[mindnoise]

, can someone tell me the best way to erase my entire hard drive, without deleting the OS X?

Hi,
besides those two statements can´t be true at the same time,

try booting from your OSX Installation CD open Disk utility and repair User Permission.

second, in the OSX Installation App there is a option by which you can install a clean OSX with keeping the old USER account. But you will loose all apps etc. that have been installed on an administrator level. The old OSX will then reside inactive inside a folder and you can get from it what else you need.

regs