virtualbox.org

I was trying to install a virtual machine to run ubuntu on my Windows 8.1 computer. I had configured everything, and when I started the virtual machine, it brought me to what I think is the Ubuntu main screen, with buttons saying "Install Ubuntu Server", "Multiple Server install with MAAS", etc. I had never intended to create a server, but I tried install Ubuntu server anyways. When I did, it opened up a console style page that said the following:
Like I said, I had never intended to install a server, so maybe my computer isn't built for it. Thanks for any possible help.

A server installation should be nothing completely different, but just a special package selection.
Perhaps not the best for you, but assuming that you install it, and it obviously is 64bit only:

Have you selected the appropriate VM template, which enables VT-x, IO-APIC etc.?
Is VT-x enabled in the host BIOS?
Is the Windows 64bit (not absolutely necessary)?

My Windows is 64 bit, and I have no idea what the other two things mean.

FAQ: I have a 64bit host, but can't install 64bit guests.

Solved. All I had to do was download a client side version of Ubuntu, and it worked fine.

Fine, but if missing VT-x was the problem, it might be a good idea to enable it anyway?