I @kaljukass, thanks for the reply. The hard drive on that pc has died so I've bought a new hard drive and I need to make a bootable usb drive with Yosemite 10.10.5. I was searching for the complete system image. Dunno if I can use the combo update.
@kaljukass That's not the thing he wants. @stefano23ps What's the exact model of the MBP? You should at least opt for El Captian though its support was already ended on last August.
after ~2 month of try /error... got it, that it's 100% intented, like by ms.... the biggest hurden was to bring 10.6 to the macbookpro (also 2008 - surprised?), because of (100% intented certificate errors as by microslop) could not get further, so i called apple support and voilla, got hot actual "upgrade"-link and el capitain is on the machine again. i felt the very clear questioning on whether 10.5 or 10.6 was on the device currently and how i did it... they know how difficult it is... i used no vm.. i converted a .dmg with cmdline tool to iso and burned DL DVD -> success!!