Mavericks crashed

[capedcrusadress]

hello everyone. I have a MacBook Pro and it's operating system just crashed. I cannot open it, it just leads me to "OS X Utilities" page, it wants me to reboot or something. There are 4 options and one of them wants me to enter my Apple ID. I do so but then it gives an error, saying "This item is temporarily unavailable". I've read in other help discussions that if your ID is not the one which set up the current OS, it doesn't accept any other secondary IDs. My computer is second hand so I don't know the first owner of the computer's ID. And I cannot use the disk utility section, while erasing disk, it says something like "we couldn't deattached your disk". Me and my dad just sat until 3 in the morning and searched for solutions. Every solution to this was having the way downloading another OS and setting it up but since we can't access to operating system we can't access to App Store, and we don't own any other Mac computer, so we're stuck. I just wanted to make sure that we have tried every possible way before going to Apple. Because there are only 2 or 3 stores in my country and I don't want my dad to pay such bills.

 

[capedcrusadress]

I have solved my problem with finding the initial Apple ID which was used for setting up Mavericks in the first place. Thread can be closed.