You have more people using one computer and you don't want them to be able to shut it down using a shutdown button on Windows logon screen, this is how you remove it.
Bookmarks are a great way to save the website addresses you don't want to forget about, this is how you add them to a stock web browser on your Samsung Galaxy S2.
VirtualBox is a great free cross-platform virtualization program that enables you to run Windows, Linux, Mac OS X and other operating systems on you Windows, OS X or Linux computer.