I had a dual boot system with Kubuntu 14.04 and Windows 7, after a long time of not using the windows I tried to boot it and all I got was a beep sound and a black screen and then the computer froze. I've tried to use windows 7 repair tools but it didn't work. afterwords I've tried to re-install windows 7, then windows came up and it worked great but when I've restored the grub so I will be able to boot to ubuntu too it had the same problem. I've looked online and re-installed grub several times, tried to changed the windows grub setup to ntldr but nothing worked and I always got the same behavior. Finally I tried to install windows 8.1. After installing it worked just as win7 worked but when I've fixed the grub to boot Ubuntu as well it stopped working. I've also tried boot-repair and this is the output it gives http://paste.ubuntu.com/8881166/
I'm trying to tackle this problem for couple of days now and any help will be highly appreciated.