Hi, My Surface Pro 3 (i5, 4, 128) is dual boot between 8.1 and Windows 10 Preview 1041. Or at least it was .. A while since when in Windows 10 the machine froze when it was plugged in to my TV. I rebooted and all seemed OK, Windows 10 was fine. Windows 8.1 was not however. It refused to run any Windows Store Apps, can't remember the error message it gave. Tracked it down to permission on ALL APPLICATIONS and got it working again, but it wouldn't play any media giving error code 0x8007005. I got fed up and decided to do a Refresh on my Windows 8 installation. I did this from a Recovery USB stick. All went OK. I re-installed desktop apps. Then I noticed that there was no option to boot in to Windows 10 on start up. I went in to recovery option and choose advanced start up and used that to reset the start menu timer to 5 seconds from the zero it was not set to. I also tried to make Windows 10 the default operating systems again. When I rebooted I got an error; "digital signature could not be verified" on \windows\system32\winload.efi error 0xc0000428 and told to press the Windows key to select a different operating system. Pressing any Windows keys made no difference at all. I researched this, went in to the BIOS boot and turned off secure boot. I can now boot in to either OS but now get a. red start up screen with the word 'Surface' in black. Looks interesting but isn't really what I want. Is there a way to make the boot up stop freaking out over winload.efi ? Anything else I can do ? I would like to be back to the point of a black boot up and two working operating systems to choose from as I was before ! Thanks for any and all help.