help re-installing entire system on imac

HELP!!

Please!!

I want to reinstall the entire system ( 9 and 10), as new for my imac. For some reason I have 4 different hard drives on my desktop, and this affects memory and more, I am still using system 9 but have both, 9 and 10, installed in my computer. The last time I tried to switch to system 10 my computer crashed/bombed, so I had to restart from disc and somehow was able to go back.
Now I want to start from new.
I have an imac, (combo drive, (NO DVD)
g4
256 memory
about 30 gb

I have all discs that came with computer.

Do you recommend that I take it to the Apple store, so a technician do the clean install , I no longer have warranty. Or is this something taht I can do at home.

Thanks, AR

Well, it is pretty easy to do a clean install (for 9 or 10). If you are gonna keep them both (9 and 10), then could be better to install 9 first.

You say that more than one disk appears in your desktop even that you have only one physical drive. In this case, each drive that appears on your desktop is a portion of your drive.
I don't think having more than one disk affects your system memory (I have a 40Gb HDD and 3 partitions on it and my machine works fine), having more than one partitions comes handy specially because you can organize better your files (or place them in a disk that does not contain your system software to keep them safe when reinstalling).

If you are gonna keep both OS9 and 10 would be better installing first OS9, you put the Mac OS Install CD (also labeled Software Install). For a clean installation, you first have to delete the current OS:

1. Deleting every Folder that belongs to the current Installation or...
2. Formating the hard disk/partition where you are gonna install or...
3. Selecting "Clean Install" from the installation program

I think it is a bit better to format the destination disk prior reinstalling (of course if you don't have important information or if you are able to place it, for example in a removable media or other existing partition other than the one you are gonna install)

After you get rid of your old system, you perform the Mac OS 9 install on the selected drive, after it finishes you have a clean install, then you can boot with your Mac OS X cd and install it in the same partition of OS9 (or other of your choice)

Hope this helps (please forgive my english since it isn't my native languaje :d)

Sorry forgot to say that the Mac OS 9 installation Cd loads Mac OS 9 from the cd so you can manipulate your existing info freely, and that there's also a utility in the Cd called "disk utility" that allows you to manage your hard disk, helping you creating/erasing partitions.

*A partition is a portion of your disk that appears as a drive in your desktop, a hard disk can contain one partition (that would use the entire capacity), two partitions (appearing as two drives in your desktop, each using a % of the hard disk) and so on...