Thanks for the answers.

I tried again and I have done this:
1) removed ethernet cable (no internet connection while installing, because
of 2&3)
2) completely uninstalled F-secure antivirus program
3) uninstalled all other security programs (also xp firewall off)
4) updated bios and chipset drivers to latest versions
5) confirmed that Nvidia Quadro drivers are the latest
6) disconnected usb-hub, and all other usb-devices (Astroid 6000) (my mouse
and keyboard are in ps/2 ports via switch)
7) tried to install from exe-file

This time the result was the same (STOP: 0x0000007F (0x80042000, 0x00000000,
0x00000000) ) blue screen while "Inspecting your system". Earlier it got pass
installing until "Performing cleanup".

I think there is something wrong with the motherboard. There has been some
problems that sometimes it cannot find harddisk (1 sata disk) when starting
computer. Usually power off and again on helps. This doesn't affect using of
computer once you got it running. It is also possible that there is some
conlict between Asus A8N -series ans Windows XP SP3, since many people are
reporting problems with those.

This aint helping much either (different error codes)
http://msinfluentials.com/blogs/jesper/archive/2008/05/08/does-your-amd-based-co
mputer-boot-after-installing-xp-sp3.aspx
Those people are having continuous reboot problem, I don't. My computer is
booting OK to safemode after failed installation of SP3 and I can get it back
to normal with System restore.

I'm not really interested calling to phone support residing in the other
side of world either.

I have some other (AMD) XP computers, but hesitate to try installing SP3 to
them, because they are our tools for working.

If someone still have suggestions what to do, those will be preciated.
I hope the solution will be found in near future.