I cannot install ubuntu 8.04 server in VirtualBox either on Ubuntu 8.04 server OS or on Vista Business OS. Does Unbuntu 8.04 server have bugs or VirtualBox have bugs?
Do you see any error messages when you try to install Ubuntu? Does this happen with Ubuntu 8.04 Desktop as well? What CPU are you using? How old is it?
"Starting up... This kernel requires the following features not present on the CPU: 0:6 Unable to boot-please use a kernel appropriate for your CPU -" It happened in two computers. 1) CPU: AMD 4200, OS: Ubuntu 8.04 Server 2) CPU: Intel Core Duo processor T2450, OS: Vista Business Have installed Ubuntu 8.04 Desktop under VirtualBox in both above computers, it works well.
Ok, this means that the Ubuntu Server kernel does not support your CPUs. It's a special kernel that requires a new CPU.