EFI Boot Sources problem? please help

[jmx91]

First of all, forgive my english. Please, I really need your help. I'm a newbie in BIOS and UEFI related stuff and I don't know how to proceed. I have read some forums seeking for a solution. I have an HP455 with AMD E1-1200 CPUs that came with suse linux and I wanted to use window 7 64 bits on it.
When I get to the part when I have to select the partition to install windows, there is a note that tells:
"windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks"

In some forum, I read that I must install windows through an USB formated with GPT.. I created it with an app called rufus, but the problem remains. I then realized that my BIOS, an InsydeH2O rev 3.7 version F.25, didn't show any hard disk information and there are hidden menus. I can see that Secure Boot is disabled (without the option to change it) and the Legacy Support is enabled. Also, there are a UEFI boot order and a Legacy Boot order, both of them enabled (I don't have the option of select boot device throw F9 at boot time)

For what I just found in this link,
http://h10025.www1.hp.com/ewfrf/wc/docum...=c03445889
I need to disable the EFI Boot Sources option, but I don't see it in the BIOS Is there an alternative? maybe it is a problem related to ACHI? (if this is true, can I use the solution Falseclock gave to a HP DV6-7280 user with the same BIOS?).. or do I need to format the partitions of the hard drive as GPT? how can I do this externally? I have deleted any partitions on my hard drive...

please help me, I just want to use windows 7