Don't buy virtualization software, get it for free:
http://www.virtualbox.org/It's what I'm using now, works fine.
You will need an installable copy, on CD/DVD media, of Windows XP to install it in any virtualization software. If your old laptop came with an installable copy of Windows, then you can use it. You cannot copy/port your installation over, no way that I know of.
I use VirtualBox w/ Windows XP, or I should say, I have it installed, but rarely use it.
A friend has VirtualBox with Windows, Solaris x86, Linux machines that he can use.
Good luck.