Download the file from here

Install it,as in the picture.





Then right click a movie file and select "set as desktop background".
Enjoy








Remember your screen resolution because you need to create a picture that its pixel same as your screen resolution.These are the resolution that supported by Windows.
You can use paint to resize the resolution of the picture that you wanted it to replace the logon background.Please note that the picture must below than 256kb.
You can also use photoshop to adjust the picture screen resolution.
configure the amount of RAM needed by the guest operating system(Windows 7 required minimum of 1G of RAM,but 512MB still can run).Windows 7 required minimum of 16GB hard disk to run.
click next
choose the hard disk storage type(choose dynamically expending storage)
click finish
a virtual machine is created in virtualbox.Now click on setting on the virtualbox user interface a windows like this will pop up.This window shows the information of your virtual machine.Tick "enable 3D acceleration",Then click OK.
Start the virtual machine and click next.
browse the Windows 7 ISO file the you have downloaded or loaded by DVD.Click next.
click next.
type your name...
product key...get it from here if you dun have one
click use recommended settings
set the date and time
configure your network setting

