Uninstalling OS X How to do it completely?

[John Erdman]

Today's Lesson : DO NOT ever, ever, ever load Keyspan's USB 10.2 
drivers onto as OS 10.2.8 system. I did it this morning and it cost  me 
a whole day to straighten it out. One effect was to  scramble something 
on my HDD so that the OS-X disc was unrecognizable even to OS 9.2.2.  
Anyhow I straightened that out.

	The solution involved installing OS 10.1.2 onto a "virgin" partition 
that was being used only for file backup.  When I did that. et voilà 
all of a sudden I could see my main partition and ultimately remove the 
offensive Keyspan files.

	Now I'm left with an unwanted version of OS 10.1.2 on that partition.  
How can I thoroughly remove the OS from that partiton? I've looked in 
the Apple knowledge base and didn't uncover any references. Nor did I 
find anything in Apple Help (but that wasn't a surprise was it?)

	Of course I can start to toss system-looking folders, but Im a little 
fearful of tossing something important. Moreover it's likely I'd miss a 
good many things. And further I'd like to remove everything the 
installer installed this AM including the apps.

Any suggestions for how to proceed from here?

Thanks
John
Peaks Island, Maine

PS: Sorry to some of you for the duplication. I'd sent the original to 
the wrong list