linux mint/windows 7 dual boot issue

Hello,

I am trying to get a dual boot with Windows 7 and Linux mint.
My system is an HP EliteBook 2560p.
I had windows 7 installed EFI.
I booted Linux mint live in EFI mode from USB and installed it on my hard drive. Instalation went ok, with no warnings or errors.
After reboot the laptop boots directly in Windows.

I have tried to boot from USB again in linux mint and to install grub but i get the error "grub-probe: error: failed to get canonical path of `/cow'"
I have searched and did not find anything that works. (I am new with linux).

Can you help me add Linux as a second boot option? I do not care if it is by using grub or using other windows boot application.

-I have tried grub-update or grub install but i get same /cow error.
-Someone suggested to install grub2 on mbr. Is this safe when both are installed EFI? How do i do that? Will i be able to boot both windows and linux if i do that?
-I tried deactivating the UEFI boot and windows did not start either. No OS was visible on start.

Thank you.
Danut

I would suggest you to disable the secure boot with UFI which is intended to assist Windows to boot only to itself and not other systems.