Hardware Specs:

CPU: AMD Phenom 8450 Triple-Core Processor 2.10 GHz
Motherboard: Asus M3A78-EM
HardDrive: 1TB WD SATA HDD
Chipset: AMD 780G / SB700
Memory: 2 x 2GB 800MHz RAM
Expansion Slots: 1 x PCI Express x16 Slot
1 x PCI Express x1 Slot
2 x PCI 2.2 Slots
Graphics/Video: Integrated ATI Raedon HD 3200 GPU
USB: 8 USB Ports
Storage Ports: 5 x SATA 3Gb/s Ports
1 x 1394 Port
Audio: Realtek ALC1200 High Definition Audio 8-Channel
LAN: Gigabit LAN
Bios: AMI BIOS

I managed to install Leopard with iDeneb 10.5.5. But after installation, Leopard wont boot up. Everything is fine untill the bootloader loads and asks to select the partition. When Leopard's partition is selected, it simply restarts.

Note:
1. I am dual booting it with Microsoft Windows Vista x64.
2. The hard drive was not getting detected in the installation. Then I changed the SATA to AHCI Mode and then it worked fine and I could proceed with the installation.
3. I went with the installation without installing a single kext provided in the installation as I couldn't find any for my hardware specs in the list provided.

PLEASE HELP!