When you install windows 10 for some reason it sets your GPU display to duel monitors so when it does its last warm reboot that brings you to the log in screen your display isn't set to default...

The update can take 1 half hours only reboot if its idling with blank screen and cursor if you have percentage on screen leave till finished

Just give it time if it gets to around 98% 99% and then it will do a last warm reboot which may take you to a blank screen with your cursor visable if this happens reboot again and press F2 or which...

This should work aujoker just find multi monitor and disable it then exit and it will carry on to the windows welcome screen

Hey thanks Arunem I have been trying to get off this blank screen since the afternoon of yesterday 29th I was on my last legs trying to get this pc back to its original status (asus g20aj too) did...

Mines been idle on the black screen for an hour now have finally switched off pc and rebooted gone straight back to blank screen and.... Nothing have to reinstall windows 8.1 and try again this is so...

started to install windows 10, 2 and half hours ago via desktop went out of the room for twenty minutes come back in a blank screen and no activity, tried rebooting with no luck stuck in this screen...