I do not know any person who installed centos 4.2 with success. Lot of my friends tried and they couldnt. So, I have tried to be the first one, because we have a bet: first who do that gets some present from the rest once. Back to the subject: when I installed it and try to boot it I got error which said that there is bootstrap failure.
Setup your bootblocks and manually create first partition to be 5 MB. Run thru the installer, then you click reboot, it won't boot because there isnt boot loader. After that boot off the cd rom again, and choose the rescue image and it will install centos.
And if it cant still boot, you can manually boot it from srm. And thas how you got the bet!