It is useful to have a copy of Ubuntu around on Windows. Dual-booting is too painful, but having Ubuntu running in a virtual machine makes it convenient to quickly try or check anything over in Linux-land. Getting Ubuntu to run in a virtual machine on Windows is really easy.
We need software that can mount an ISO file as a drive under Windows. I have used Virtual CloneDrive for many years for this purpose.
Download the ISO file of Ubuntu and mount it as a drive using Virtual CloneDrive.
VirtualBox is a simple virtual machine for Windows that can host Ubuntu. Download and install it.
Run VirtualBox. Choose to create a new virtual machine. Choose Ubuntu and click Next on all the dialogs so that the default settings are chosen. When asked to pick the installation media, pick the drive where the Ubuntu ISO is mounted. You should be able to boot the Ubuntu install disc and install it. This will take quite a while and you will be required to pick a timezone and create a username. After the install is over, unmount the ISO. You can now open Ubuntu whenever you want under Windows.
Tried with: Virtual CloneDrive 220.127.116.11, Ubuntu 11.10, VirtualBox 4.1.10 and Windows 7