* You MUST set single core mode in bios! *
1. Acquire Kalyway Leo 10.5.1 Intel Install Image.
2. Acquire Kalyway 10.5.2 Combo Update
3. Install the 10.5.1 Intel Image (just as you would any other OS.)
4. When it boots up and asks for configuration options open up disk utility and set your partitions correctly (If your sharing the drive with windows just make a new partition, if your using a new disk format however you wish).
5. Continue through the installation until you see the screen with the install 'Install' button. Click 'Customize' in the lower left hand corner. Make sure EFI is selected for MBR (if your sharing the drive with a windows partition) or GUID (If its a new disk you just formated). No other options need to be installed.
6. When the installer finishes you can now boot into a working leopard 10.5.1! The only problem is sound wont be working!
7. Use the sound file found on the first page of this thread ( attachment: d620_sounds ). Download that file and uncompress it. Drag the included .txt file onto the HDAPatcher included and let it do its thing. Reboot when its done.
8. Now sound works too! Woohoo! Lets update the install now!
9. Run the 10.5.2 Combo Update file you acquired earlier. Let it do its thing and restart when required. The computer will restart and fail to boot properly. This is OK! The next time it boots it should work perfectly. You know have 10.5.2 installed! Now lets finish off a few things (getting speedstep working, battery icon showing, etc...)
10. Download the pack i have attached below. It is based off of another pack rumaging around the net, but i included all of my own personal files and such for my own D620, so they should work just right for you!

http://www.novicee.com/edu/Speedstep.zip

*** ALL CREDIT FOR THIS WONDERFUL PACK IS PAID TO http://minsong79.tistory.com/10. I have Modified it for the D620 specifically, but original pack was found there! ***

11. Follow the instructions included in the zip file below, using the files included below
12. Congratulations, you now have a fully working, fully upgraded D620 running Leopard!

BUT WAIT, THERES POTENTIALLY MORE!

You can feel free to get software updates from the built in apple software updated, however if you install the 'Leopard Graphics Pack' that it tells you you should your computer will no longer boot correctly! Uh oh! You have two choices here now.

1. Dont Download it.
2. Download it and MAKE IT WORK!

Ill assume your an adventurous guy (hey, i hope you are ) and want to do the second option. No problem, but some more steps are needed....

1. Backup your AppleIntelIntegratedFrameBuffer.kext file located in System/Library/Extensions (simply dragging it to your desktop will work fine. Infact, ill be assuming thats what you did below...)
2. Use the auto-update feature to get the updated. Reboot when it says its neccessary.
3. When you reboot youll see your boot menu and it will say press a button to enter a custom command. Press a button.
4. Enter '-s' (without either ') and press Entere.
5. When its done doing a bunch of scary text stuff and is waiting for your input type the following:

6. Now type the following (this is assuming you simply dragged the FrameBuffer.kext to your desktop before:

It will ask for your password. Enter it.