Solved the issue.
I couldn't use the bios updater executable.
But I was able to update the bios using:
Gigabytes "motherboard_utility_gbttools_gbt_atbios"
And yes... I know there might not be a big reason to update the bios.
And I know there's always a small chance of turning it into a useless piece of plastic
But .... I just like to live dangeriously
... also...
it'll cost me € 100,- to replace it in that case, so... it's not that big a gamble imho.
Thx for your help anyways !