Trying to upgrade from 10.5.8 to 10.6 ... help!

[lolalola]

I'm having no luck attempting to install OSX Snow Leopard onto my iMac, please help!

Ok, I currently have 10.5.8 installed, and I only want to UPGRADE to 10.6, not completely erase everything by doing a clean install or anything.
Here's what happens (pics below too) :

1/ insert the OSX Snow Leopard dvd.
2/It asks me to partition my hard disk.
I try doing that, but it fails, with the message "Filesystem verify or repair failed"

..!? What can I do?

 

[Kaveman]

This volume is the Startup volume, it can not be erased.

 

[Cory Cooper]

The reason you can't install it is because it is formatted as Apple Partition Map and not GUID. GUID is required for booting an Intel Mac. As Kaveman said, you cannot partition the internal HD when booted from it.

To get SL installed you will have to do the following:

1. ***IMPORTANT*** Backup all of your data using Time Machine or cloning software like Carbon Copy Cloner or SuperDuper! If you don't do this step, you will lose all of your data.
2. Boot from installer disc, select the internal HD and choose Partition. Use Mac OS Extended (Journaled) and choose GUID under the Options section. (I would disconnect all external HDs before partitioning internal HD, to prevent selecting the wrong HD.
3. When done, quit Disk Utility and it will go back to the installer.
4. Choose the internal HD that you just partitioned and complete the install.
5. When it is complete, it will restart.
6. Depending on how you backed up your data determines the next step. Let us know and we can post the steps to migrate your data to the cleanly installed system.

Again, I stress make a backup before performing the erase & install or you will lose all your data. Let us know if you have further questions before beginning.

C