Charly said:
Oh well, never ending odyssee.
The manufacturer provides a bios download for windows serverX64 2003 maybe try that?

Shaggy410 said:
It looks like an issue with UEFI and a way too old Windows version (since you mention it doesn't have legacy support on BIOS), you can give it a try with a Server 2008 or newer if possible, since from that version onwards Microsoft implemented full UEFI support into Server OS's
That would be a good solution if Charly already has a later version of MS Server. But if he does not and If he is only using the computer as a file server, he could also download Ubuntu, and have a current OS that is free.