"Previous Linux versions" is currently untranslatable. That said, I consider that string to be in flux - we may redesign that submenu.
"Memory Test" and "serial console" are handled by the memtest86+ package, not by grub2. There is no way to translate strings supplied by external packages right now.
"Windows Vista (loader)" and "(on /dev/sda2)" are generated dynamically by os-prober. Translating these is going to be extremely difficult.
I don't expect a solution for any of these in the near future - sorry.
"Previous Linux versions" is currently untranslatable. That said, I consider that string to be in flux - we may redesign that submenu.
"Memory Test" and "serial console" are handled by the memtest86+ package, not by grub2. There is no way to translate strings supplied by external packages right now.
"Windows Vista (loader)" and "(on /dev/sda2)" are generated dynamically by os-prober. Translating these is going to be extremely difficult.
I don't expect a solution for any of these in the near future - sorry.