can't reboot with microsoft keyboard? ctrl R dont work

Hi.

Im on a mac mini with hewlett packard keyboard and mouse.
Afrer research the ctrl should be command on a microsoft keyboard but when i restart the mac and hold ctrl and R nothing happend.

How could i reset the computer when i dont get into the setup menu with my microsoft keyboard?

Any idea? Im selling it and i dont want to buy a apple keyboard just to restore it and install yosemite..

Thanks for any help i could get