The CD's that come with laptops tend to be factory restore discs and
running them will want to erase the whole HD and put Windows on as the
only OS - as delivered from the factory. What you'd need is a plain
Vista install CD to be able to load in into Virtual Box as a VM. In
fact that applies to any OS you care to install in Virtual Box, you
will need an installation CD or ISO file.

It may be that you can coax the factory restore disc to work but the
chances are that it will see the Virtual Machine as not the original
hardware it was designed to load onto and refuse to load.

Anyway - warnings aside and it you wish to try it the general way is
to first of all create a new VM and tell it what OS you are going to
install then decide on the virtual HD size ( you can select a dynamic
size but this has down sides in terms of performance ). Once the VM is
created, go through the settings and check the boot order to be CD
first in 'System' and also select 'Pass through' in the 'Storage' so
that the CD/DVD drive is seen.

Now pop the Vista CD in the drive and cancel any auto-run then launch
the Vista VM and follow the prompts as normal when installing Windows.
You may get messages about the mouse and keyboard capture - just
cancel for now and when Vista is running you can install Guest
Additions from the 'Devices' menu drop down list which will make
moving the mouse from the VM to Ubuntu seamless.

Been a long time user of Virtual Box in Ubuntu so sing out for any
help you may need