so ive downloaded Ubuntu and burned it onto a disc, installed it, rebooted, and Windows wont let me use Ubuntu. I chose to run Ubuntu with Windows. What i saw on youtube was when you restart your computer before Windows launches you can either choose Windows or Ubuntu. However that screen will not show and automatically boots Windows.  this is very frustrating. anybody have any experience with Ubuntu installation or has had this problem and would like to help? Im all ears...or should i say eyes hahaha but seriously id like some help with this.