Re-install Mac mini Server My friend gave me Mac mini Server saying its Mavericks. When I switch it on I see 2 hard drives only and no operating system. I tried to use my Apple ID but it doesn't work. In disk utility I saw 1st hard drive has partition named "os" which I am not able to delete. How do I completely format both the hard drives and re-install Mavericks on that. I have a very slow internet and I don't have another mac, of course I have Linux and Windows dual boot machine.
In disk utility via safe mode, you should be able to format it completely by wiping the disk.

Then after wiping the disk, boot into a DVD or USB of OS X and reformat from there.