8/8/15 I upgraded from Windows 7 to Windows 10, and after Windows10 installed I made Firefox my default browser and shut down my PC, waited 15 seconds and powered up the PC and didn't even expect that it would give me an option to still choose Ubuntu within 5 seconds.I clicked Ubuntu and it seemed to hang in limbo with a grey screen for what seemed an eternity , but I didn't do anything except tapped the enter button on the keyboard to attempt get something to happen and waited , then finally the familiar black screen to choose Ubuntu or advanced options appeared. It booted up in Ubuntu fine. After I shut off and powered up in windows 10, the time and date in Windows showed 5 hours fast, just like windows 7 did after using Ubuntu, LOL. Next time I chose Ubuntu to boot the boot up wait was a lot shorter.