CentOS 5 fail to install on VirtualBox

How to fix Kernel freeze problem when installing CentOS 5 on a VirtualBox guest.

Problem

When installing CentOS 5.x on a VirtualBox guest you may see that the installation freeze without going any further and the last message on screen is:

NET: Registered protocol family 2

Solution

It's actually quite easy to solve this problem, you just have to enable IO APIC in your guest machine.

Open CentOS guest machine Settings, then go to System and select the checkbox Enable IO APIC.

Danilo