fail to erase partition

I want to install iPC 10.5.6 into an system Dell Inspiron 530, with Windows 7.
So I created a new partition (fat32), I booted using the DVD with the iPC, but when I want to erase partition on which to install Mac, nothing happens. Partition remain in original format. I can not proceed with installation.

System spec:
CPU Type DualCore Intel Core 2 Duo E8400
Instruction Set x86, x86-64, MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1
Total memory 2037 MB
Motherboard Name Dell Inspiron 530
Intel GMA 3100 Video Adapter
Network Adapter Intel(R) 82562V-2 10/100 Network Connection
HDD WDC WD2500AAJS-75B4A0 ATA Device

How to solve this problem?

Are you trying with Extended Journaled rite? try adding zeros to the partition

Yes, i try to use Extended Journaled. I will try tomorrow, and I will post results.

I tried today, adding zeros to the partition, but without success.
I don't know where it's the problem. He can mount even when partition is FAT32.