How can I stop Ubuntu from being the default operating system on my dual-boot machine?

I have a desktop PC on which I have installed both Windows XP and the Ubuntu operating system. Until recently Windows XP was set as the default operating system, starting automatically 10 seconds after the computer was switched on. Recently, though, I was invited to upgrade to Ubuntu 11, which I did, and now Ubuntu… Continue reading How can I stop Ubuntu from being the default operating system on my dual-boot machine?