Deactivate Secure Boot; Win8 doesnt boot after installation of Ubuntu 12.04.2 LTS

[RostigerNagel1]

On my Sony Vaio SVF1521C5E was Win 8 preinstalled.
As a Ubuntu-fan, I decided to additionally install Ubuntu 12.04.2 LTS for an dual-boot system.
After the installation Ubuntu can be booted, but if I want to select Windows 8 the following error message appears:
"error: unkown command 'drivemap'.
error: invalid EFI file path."
After a few seconds it returns to the previous page, where I can select Ubuntu and Win8, but Win8 does not boot.

As you can see in the attached file SecureBoot should be disabled, but it seems to be activated.
For less than 1s at the booting screen appears "Secure Boot forbids loading module from (hd0, gpt7)/boot/grub/gettext.mod." before I see the Grub2 page.

How can I be sure, if SecureBoot is deaktivated? If I use the "Assist" key, I see the attached entry, but the error message and the signed kernel which is for secure boot is a hint for activated SecureBoot.
Is there an other possibility to deactivate SecureBoot?

The results of the BootInfo you can find in Ubuntu Pastebin .

I hope, that somebody can help me!

Please help me!!!

(You can also reply in German.)

[djkalle]

zur Info ::

http://www.pc-magazin.de/ratgeber/gpt-und-mbr-im-vergleich-822496.html


http://wiki.ubuntuusers.de/GRUB_2/Grundlagen

[-Luka-]

Dear RostigerNagel1,

Welcome to the Sony forum. Since this is a German forum, you have a better chance of  getting a response by posting your question in German. You can also navigate to the english site in order to access the English speaking forums.

Kind regards,

-Luka-