@lugmor
Sounds like you've got the nvidia "kernel panic" because you didn't boot in "safe mode" and haven't removed the nvidia related .kexts from the /System/Library/Extensions folder.

See this: http://osx86.wikidot.com/known-issues#toc1

You can do the same thing this way:
Start or Restart the computer - boot off installation HD
Press any key during the "boot options" countdown
type: -x
hit Enter - this starts OSX in "safe mode"
It should eventually start the graphical mode and enter the Initial Setup screens.
If you make it safely past "Account Creation", you'll be in the OS X Desktop
Use "Finder" - choose your install disk and navigate through these folders:
System / Library / Extensions
In the Extensions folder move ALL .kext files that begin "geforce" ( geforce*.kext ) to the Trash bin
Do the same with all files that begin "nv*.kext - they're all nvidia related.
Empty the Trash bin to permanently delete these files.
You should be able to Restart and boot into the Desktop normally from here.
The next step is to find the proper .kexts or installer for your video card (and other hardware that may not yet be working properly...

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Running both 10.5.8 and 10.6.4 on my stinking AMD/ATi machine...