Thanks for replies, but it doesn't wanna work:/

It doesn't wanna create .mkext file as you said.

I've got some old logitech keyboard and some shitty A4tech mouse.

"Task: Pack "/Volumes/Snow Leo/System/Library/Extensions"
to "/Volumes/Snow Leo/System/Library/Extensions.mkext"

Repair Permissions for "/Volumes/Snow Leo/System/Library/Extensions" ... Done.
-- Total processed: 4902 files for 50 sec.
kext: 300
plugin: 23
bundle: 18
ppp: 10

Search "Extensions.mkext" ... Not Found.

Packing new "Extensions.mkext" ...
Sorry, could not create "Extensions.mkext""

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CPU:C2D E4400@3GHz
GPU: 8800 GTS 640MB
MOBO: Gigabyte P35C-DS3R
RAM: 4GB OCz 800MHz Platinum rev. 2
HDDs: 1x 250GB SATA, 1x 500GB SATA (both from Seagate)
DISPLAY: Flatron L1960TR

Running iPC 10.5.6(10.5.7 updated)
Trying to instal Snow...without success:/