Dear friends
On my HP Envy dv6-7350sl just bough with Window 8,
I upgraded to Windows 8.1,
then installed Kubuntu 13.10 (64bit).
=> On the Grub menu I got the boot hanging on both Windows and Kubuntu/Ubuntu.
So I launched Boot Repair 64bit for Ubuntu 13.04.
=> Only improvement is with new Windows choices it does not hang but come back to GRUB menu...

Boot-Info URL from Boot Repair :
begore repair: http://paste.ubuntu.com/6843899
after repair: http://paste.ubuntu.com/6844087

Thank you a lot for the support!!!
renzanel

Windows boot recovered (2 february):

SUCCEEDED TO BOOT Windows (NOT YET UBUNTU):
from BIOS setup : Secure Boot Disable

from Windows command prompt:
X:\Windows\sysyem32\bootrec /FixMbr

from HP Recovery Menu > HP Recovery Manager
restore previous status at date ...
=> from GRUB Menu > now Windows 8.1 starts up !

I imagine as follows:

you have 2 OS's in your laptop Win 8.1 and Kubuntu. You want to be able to choose desired OS at boot time.
So on Win 8.1 boot-menu you have two systems listed. When you choose Win 8.1 it will be started, when you choose Kubuntu, you are redirected to GRUB. Am I correct?

Hi,
At boot the GRUB menu appears. All right with Windows.
Selecting "kubuntu" the PC hangs on a black screen.
Selecting "kubuntu with linux 3.11.0-15 generic" is the same.
Selecting "kubuntu with linux 3.11.015 recovery" : the recovery menu appears. So far I did not select fsck or grub as I fear to block again Windows. I selected "resume" and a log page appeared with:
- load essent.drivers: done
- mounting root file sys.: done
- WARNING: fake initctl called, doing nothing

Thank you a lot
renzanel